601 lines
24 KiB
C++
601 lines
24 KiB
C++
/**
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* \file Utility.hpp
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* \brief Header for GeographicLib::Utility class
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*
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* Copyright (c) Charles Karney (2011-2022) <charles@karney.com> and licensed
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* under the MIT/X11 License. For more information, see
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* https://geographiclib.sourceforge.io/
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**********************************************************************/
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#if !defined(GEOGRAPHICLIB_UTILITY_HPP)
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#define GEOGRAPHICLIB_UTILITY_HPP 1
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#include <GeographicLib/Constants.hpp>
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#include <iomanip>
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#include <vector>
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#include <sstream>
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#include <cctype>
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#include <ctime>
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#include <cstring>
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#if defined(_MSC_VER)
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// Squelch warnings about constant conditional expressions and unsafe gmtime
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# pragma warning (push)
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# pragma warning (disable: 4127 4996)
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#endif
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namespace GeographicLib {
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/**
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* \brief Some utility routines for %GeographicLib
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*
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* Example of use:
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* \include example-Utility.cpp
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**********************************************************************/
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class GEOGRAPHICLIB_EXPORT Utility {
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private:
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static bool gregorian(int y, int m, int d) {
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// The original cut over to the Gregorian calendar in Pope Gregory XIII's
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// time had 1582-10-04 followed by 1582-10-15. Here we implement the
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// switch over used by the English-speaking world where 1752-09-02 was
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// followed by 1752-09-14. We also assume that the year always begins
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// with January 1, whereas in reality it often was reckoned to begin in
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// March.
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return 100 * (100 * y + m) + d >= 17520914; // or 15821015
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}
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static bool gregorian(int s) {
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return s >= 639799; // 1752-09-14
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}
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public:
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/**
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* Convert a date to the day numbering sequentially starting with
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* 0001-01-01 as day 1.
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*
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* @param[in] y the year (must be positive).
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* @param[in] m the month, Jan = 1, etc. (must be positive). Default = 1.
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* @param[in] d the day of the month (must be positive). Default = 1.
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* @return the sequential day number.
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**********************************************************************/
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static int day(int y, int m = 1, int d = 1);
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/**
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* Convert a date to the day numbering sequentially starting with
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* 0001-01-01 as day 1.
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*
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* @param[in] y the year (must be positive).
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* @param[in] m the month, Jan = 1, etc. (must be positive). Default = 1.
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* @param[in] d the day of the month (must be positive). Default = 1.
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* @param[in] check whether to check the date.
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* @exception GeographicErr if the date is invalid and \e check is true.
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* @return the sequential day number.
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**********************************************************************/
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static int day(int y, int m, int d, bool check);
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/**
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* Given a day (counting from 0001-01-01 as day 1), return the date.
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*
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* @param[in] s the sequential day number (must be positive)
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* @param[out] y the year.
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* @param[out] m the month, Jan = 1, etc.
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* @param[out] d the day of the month.
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**********************************************************************/
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static void date(int s, int& y, int& m, int& d);
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/**
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* Given a date as a string in the format yyyy, yyyy-mm, or yyyy-mm-dd,
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* return the numeric values for the year, month, and day. No checking is
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* done on these values. The string "now" is interpreted as the present
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* date (in UTC).
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*
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* @param[in] s the date in string format.
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* @param[out] y the year.
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* @param[out] m the month, Jan = 1, etc.
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* @param[out] d the day of the month.
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* @exception GeographicErr is \e s is malformed.
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**********************************************************************/
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static void date(const std::string& s, int& y, int& m, int& d);
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/**
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* Given the date, return the day of the week.
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*
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* @param[in] y the year (must be positive).
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* @param[in] m the month, Jan = 1, etc. (must be positive).
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* @param[in] d the day of the month (must be positive).
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* @return the day of the week with Sunday, Monday--Saturday = 0,
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* 1--6.
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**********************************************************************/
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static int dow(int y, int m, int d) { return dow(day(y, m, d)); }
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/**
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* Given the sequential day, return the day of the week.
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*
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* @param[in] s the sequential day (must be positive).
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* @return the day of the week with Sunday, Monday--Saturday = 0,
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* 1--6.
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**********************************************************************/
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static int dow(int s) {
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return (s + 5) % 7; // The 5 offset makes day 1 (0001-01-01) a Saturday.
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}
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/**
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* Convert a string representing a date to a fractional year.
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*
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* @tparam T the type of the argument.
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* @param[in] s the string to be converted.
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* @exception GeographicErr if \e s can't be interpreted as a date.
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* @return the fractional year.
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*
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* The string is first read as an ordinary number (e.g., 2010 or 2012.5);
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* if this is successful, the value is returned. Otherwise the string
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* should be of the form yyyy-mm or yyyy-mm-dd and this is converted to a
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* number with 2010-01-01 giving 2010.0 and 2012-07-03 giving 2012.5. The
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* string "now" is interpreted as the present date.
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**********************************************************************/
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template<typename T> static T fractionalyear(const std::string& s) {
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try {
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return val<T>(s);
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}
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catch (const std::exception&) {}
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int y, m, d;
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date(s, y, m, d);
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int t = day(y, m, d, true);
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return T(y) + T(t - day(y)) / T(day(y + 1) - day(y));
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}
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/**
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* Convert a object of type T to a string.
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*
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* @tparam T the type of the argument.
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* @param[in] x the value to be converted.
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* @param[in] p the precision used (default −1).
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* @exception std::bad_alloc if memory for the string can't be allocated.
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* @return the string representation.
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*
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* If \e p ≥ 0, then the number fixed format is used with \e p bits of
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* precision. With \e p < 0, there is no manipulation of the format,
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* except that <code>boolalpha</code> is used to represent bools as "true"
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* and "false". There is an overload of this function if T is Math::real;
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* this deals with inf and nan.
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**********************************************************************/
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template<typename T> static std::string str(T x, int p = -1) {
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std::ostringstream s;
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if (p >= 0) s << std::fixed << std::setprecision(p);
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s << std::boolalpha << x; return s.str();
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}
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/**
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* Trim the white space from the beginning and end of a string.
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*
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* @param[in] s the string to be trimmed
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* @return the trimmed string
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**********************************************************************/
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static std::string trim(const std::string& s);
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/**
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* Lookup up a character in a string.
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*
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* @param[in] s the string to be searched.
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* @param[in] c the character to look for.
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* @return the index of the first occurrence character in the string or
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* −1 is the character is not present.
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*
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* \e c is converted to upper case before search \e s. Therefore, it is
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* intended that \e s should not contain any lower case letters.
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**********************************************************************/
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static int lookup(const std::string& s, char c);
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/**
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* Lookup up a character in a char*.
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*
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* @param[in] s the char* string to be searched.
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* @param[in] c the character to look for.
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* @return the index of the first occurrence character in the string or
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* −1 is the character is not present.
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*
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* \e c is converted to upper case before search \e s. Therefore, it is
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* intended that \e s should not contain any lower case letters.
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**********************************************************************/
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static int lookup(const char* s, char c);
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/**
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* Convert a string to type T.
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*
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* @tparam T the type of the return value.
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* @param[in] s the string to be converted.
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* @exception GeographicErr is \e s is not readable as a T.
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* @return object of type T.
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*
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* White space at the beginning and end of \e s is ignored.
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*
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* Special handling is provided for some types.
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*
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* If T is a floating point type, then inf and nan are recognized.
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*
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* If T is bool, then \e s should either be string a representing 0 (false)
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* or 1 (true) or one of the strings
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* - "false", "f", "nil", "no", "n", "off", or "" meaning false,
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* - "true", "t", "yes", "y", or "on" meaning true;
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* .
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* case is ignored.
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*
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* If T is std::string, then \e s is returned (with the white space at the
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* beginning and end removed).
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**********************************************************************/
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template<typename T> static T val(const std::string& s) {
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// If T is bool, then the specialization val<bool>() defined below is
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// used.
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T x;
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std::string errmsg, t(trim(s));
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do { // Executed once (provides the ability to break)
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std::istringstream is(t);
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if (!(is >> x)) {
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errmsg = "Cannot decode " + t;
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break;
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}
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int pos = int(is.tellg()); // Returns -1 at end of string?
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if (!(pos < 0 || pos == int(t.size()))) {
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errmsg = "Extra text " + t.substr(pos) + " at end of " + t;
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break;
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}
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return x;
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} while (false);
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x = std::numeric_limits<T>::is_integer ? 0 : nummatch<T>(t);
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if (x == 0)
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throw GeographicErr(errmsg);
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return x;
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}
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/**
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* Match "nan" and "inf" (and variants thereof) in a string.
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*
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* @tparam T the type of the return value (this should be a floating point
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* type).
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* @param[in] s the string to be matched.
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* @return appropriate special value (±∞, nan) or 0 if none is
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* found.
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*
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* White space is not allowed at the beginning or end of \e s.
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**********************************************************************/
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template<typename T> static T nummatch(const std::string& s) {
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if (s.length() < 3)
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return 0;
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std::string t(s);
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for (std::string::iterator p = t.begin(); p != t.end(); ++p)
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*p = char(std::toupper(*p));
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for (size_t i = s.length(); i--;)
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t[i] = char(std::toupper(s[i]));
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int sign = t[0] == '-' ? -1 : 1;
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std::string::size_type p0 = t[0] == '-' || t[0] == '+' ? 1 : 0;
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std::string::size_type p1 = t.find_last_not_of('0');
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if (p1 == std::string::npos || p1 + 1 < p0 + 3)
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return 0;
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// Strip off sign and trailing 0s
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t = t.substr(p0, p1 + 1 - p0); // Length at least 3
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if (t == "NAN" || t == "1.#QNAN" || t == "1.#SNAN" || t == "1.#IND" ||
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t == "1.#R")
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return Math::NaN<T>();
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else if (t == "INF" || t == "1.#INF" || t == "INFINITY")
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return sign * Math::infinity<T>();
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return 0;
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}
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/**
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* Read a simple fraction, e.g., 3/4, from a string to an object of type T.
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*
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* @tparam T the type of the return value.
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* @param[in] s the string to be converted.
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* @exception GeographicErr is \e s is not readable as a fraction of type
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* T.
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* @return object of type T
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*
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* \note The msys shell under Windows converts arguments which look like
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* pathnames into their Windows equivalents. As a result the argument
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* "-1/300" gets mangled into something unrecognizable. A workaround is to
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* use a floating point number in the numerator, i.e., "-1.0/300". (Recent
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* versions of the msys shell appear \e not to have this problem.)
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**********************************************************************/
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template<typename T> static T fract(const std::string& s) {
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std::string::size_type delim = s.find('/');
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return
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!(delim != std::string::npos && delim >= 1 && delim + 2 <= s.size()) ?
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val<T>(s) :
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// delim in [1, size() - 2]
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val<T>(s.substr(0, delim)) / val<T>(s.substr(delim + 1));
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}
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/**
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* Read data of type ExtT from a binary stream to an array of type IntT.
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* The data in the file is in (bigendp ? big : little)-endian format.
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*
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* @tparam ExtT the type of the objects in the binary stream (external).
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* @tparam IntT the type of the objects in the array (internal).
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* @tparam bigendp true if the external storage format is big-endian.
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* @param[in] str the input stream containing the data of type ExtT
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* (external).
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* @param[out] array the output array of type IntT (internal).
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* @param[in] num the size of the array.
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* @exception GeographicErr if the data cannot be read.
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**********************************************************************/
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template<typename ExtT, typename IntT, bool bigendp>
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static void readarray(std::istream& str, IntT array[], size_t num) {
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#if GEOGRAPHICLIB_PRECISION < 4
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if (sizeof(IntT) == sizeof(ExtT) &&
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std::numeric_limits<IntT>::is_integer ==
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std::numeric_limits<ExtT>::is_integer)
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{
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// Data is compatible (aside from the issue of endian-ness).
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str.read(reinterpret_cast<char*>(array), num * sizeof(ExtT));
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if (!str.good())
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throw GeographicErr("Failure reading data");
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if (bigendp != Math::bigendian) { // endian mismatch -> swap bytes
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for (size_t i = num; i--;)
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array[i] = Math::swab<IntT>(array[i]);
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}
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}
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else
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#endif
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{
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const int bufsize = 1024; // read this many values at a time
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ExtT buffer[bufsize]; // temporary buffer
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int k = int(num); // data values left to read
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int i = 0; // index into output array
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while (k) {
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int n = (std::min)(k, bufsize);
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str.read(reinterpret_cast<char*>(buffer), n * sizeof(ExtT));
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if (!str.good())
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throw GeographicErr("Failure reading data");
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for (int j = 0; j < n; ++j)
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// fix endian-ness and cast to IntT
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array[i++] = IntT(bigendp == Math::bigendian ? buffer[j] :
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Math::swab<ExtT>(buffer[j]));
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k -= n;
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}
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}
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return;
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}
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/**
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* Read data of type ExtT from a binary stream to a vector array of type
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* IntT. The data in the file is in (bigendp ? big : little)-endian
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* format.
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*
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* @tparam ExtT the type of the objects in the binary stream (external).
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* @tparam IntT the type of the objects in the array (internal).
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* @tparam bigendp true if the external storage format is big-endian.
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* @param[in] str the input stream containing the data of type ExtT
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* (external).
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* @param[out] array the output vector of type IntT (internal).
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* @exception GeographicErr if the data cannot be read.
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**********************************************************************/
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template<typename ExtT, typename IntT, bool bigendp>
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static void readarray(std::istream& str, std::vector<IntT>& array) {
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if (array.size() > 0)
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readarray<ExtT, IntT, bigendp>(str, &array[0], array.size());
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}
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/**
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* Write data in an array of type IntT as type ExtT to a binary stream.
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* The data in the file is in (bigendp ? big : little)-endian format.
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*
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* @tparam ExtT the type of the objects in the binary stream (external).
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* @tparam IntT the type of the objects in the array (internal).
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* @tparam bigendp true if the external storage format is big-endian.
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* @param[out] str the output stream for the data of type ExtT (external).
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* @param[in] array the input array of type IntT (internal).
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* @param[in] num the size of the array.
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* @exception GeographicErr if the data cannot be written.
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**********************************************************************/
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template<typename ExtT, typename IntT, bool bigendp>
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static void writearray(std::ostream& str, const IntT array[], size_t num)
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{
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#if GEOGRAPHICLIB_PRECISION < 4
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if (sizeof(IntT) == sizeof(ExtT) &&
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std::numeric_limits<IntT>::is_integer ==
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std::numeric_limits<ExtT>::is_integer &&
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bigendp == Math::bigendian)
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{
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// Data is compatible (including endian-ness).
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str.write(reinterpret_cast<const char*>(array), num * sizeof(ExtT));
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if (!str.good())
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throw GeographicErr("Failure writing data");
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}
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else
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#endif
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{
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const int bufsize = 1024; // write this many values at a time
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ExtT buffer[bufsize]; // temporary buffer
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int k = int(num); // data values left to write
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int i = 0; // index into output array
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while (k) {
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int n = (std::min)(k, bufsize);
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for (int j = 0; j < n; ++j)
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// cast to ExtT and fix endian-ness
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buffer[j] = bigendp == Math::bigendian ? ExtT(array[i++]) :
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Math::swab<ExtT>(ExtT(array[i++]));
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str.write(reinterpret_cast<const char*>(buffer), n * sizeof(ExtT));
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if (!str.good())
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throw GeographicErr("Failure writing data");
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k -= n;
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}
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}
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return;
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}
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/**
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* Write data in an array of type IntT as type ExtT to a binary stream.
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* The data in the file is in (bigendp ? big : little)-endian format.
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*
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* @tparam ExtT the type of the objects in the binary stream (external).
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* @tparam IntT the type of the objects in the array (internal).
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* @tparam bigendp true if the external storage format is big-endian.
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* @param[out] str the output stream for the data of type ExtT (external).
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* @param[in] array the input vector of type IntT (internal).
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* @exception GeographicErr if the data cannot be written.
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**********************************************************************/
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template<typename ExtT, typename IntT, bool bigendp>
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static void writearray(std::ostream& str, std::vector<IntT>& array) {
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if (array.size() > 0)
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writearray<ExtT, IntT, bigendp>(str, &array[0], array.size());
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}
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/**
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* Parse a KEY [=] VALUE line.
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*
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* @param[in] line the input line.
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* @param[out] key the KEY.
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* @param[out] value the VALUE.
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* @param[in] equals character representing "equals" to separate KEY and
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* VALUE, if NULL (the default) use first space character.
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* @param[in] comment character to use as the comment character; if
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* non-NULL, this character and everything after it is discarded; default
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* is '#'.
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* @exception std::bad_alloc if memory for the internal strings can't be
|
|
* allocated.
|
|
* @return whether a key was found.
|
|
*
|
|
* The \e comment character (default is '#') and everything after it are
|
|
* discarded and the result trimmed of leading and trailing white space.
|
|
* Use the \e equals delimiter character (or, if it is NULL -- the default,
|
|
* the first white space) to separate \e key and \e value. \e key and \e
|
|
* value are trimmed of leading and trailing white space. If \e key is
|
|
* empty, then \e value is set to "" and false is returned.
|
|
**********************************************************************/
|
|
static bool ParseLine(const std::string& line,
|
|
std::string& key, std::string& value,
|
|
char equals = '\0', char comment = '#');
|
|
|
|
/**
|
|
* Set the binary precision of a real number.
|
|
*
|
|
* @param[in] ndigits the number of bits of precision. If ndigits is 0
|
|
* (the default), then determine the precision from the environment
|
|
* variable GEOGRAPHICLIB_DIGITS. If this is undefined, use ndigits =
|
|
* 256 (i.e., about 77 decimal digits).
|
|
* @return the resulting number of bits of precision.
|
|
*
|
|
* This only has an effect when GEOGRAPHICLIB_PRECISION = 5. The
|
|
* precision should only be set once and before calls to any other
|
|
* GeographicLib functions. (Several functions, for example Math::pi(),
|
|
* cache the return value in a static local variable. The precision needs
|
|
* to be set before a call to any such functions.) In multi-threaded
|
|
* applications, it is necessary also to set the precision in each thread
|
|
* (see the example GeoidToGTX.cpp).
|
|
*
|
|
* \note Use Math::digits() to return the current precision in bits.
|
|
**********************************************************************/
|
|
static int set_digits(int ndigits = 0);
|
|
|
|
};
|
|
|
|
/**
|
|
* The specialization of Utility::val<T>() for strings.
|
|
*
|
|
* @param[in] s the string to be converted.
|
|
* @exception GeographicErr is \e s is not readable as a T.
|
|
* @return the string trimmed of its whitespace.
|
|
**********************************************************************/
|
|
template<> inline std::string Utility::val<std::string>(const std::string& s)
|
|
{ return trim(s); }
|
|
|
|
/**
|
|
* The specialization of Utility::val<T>() for bools.
|
|
*
|
|
* @param[in] s the string to be converted.
|
|
* @exception GeographicErr is \e s is not readable as a T.
|
|
* @return boolean value.
|
|
*
|
|
* \e s should either be string a representing 0 (false)
|
|
* or 1 (true) or one of the strings
|
|
* - "false", "f", "nil", "no", "n", "off", or "" meaning false,
|
|
* - "true", "t", "yes", "y", or "on" meaning true;
|
|
* .
|
|
* case is ignored.
|
|
**********************************************************************/
|
|
template<> inline bool Utility::val<bool>(const std::string& s) {
|
|
std::string t(trim(s));
|
|
if (t.empty()) return false;
|
|
bool x;
|
|
{
|
|
std::istringstream is(t);
|
|
if (is >> x) {
|
|
int pos = int(is.tellg()); // Returns -1 at end of string?
|
|
if (!(pos < 0 || pos == int(t.size())))
|
|
throw GeographicErr("Extra text " + t.substr(pos) +
|
|
" at end of " + t);
|
|
return x;
|
|
}
|
|
}
|
|
for (std::string::iterator p = t.begin(); p != t.end(); ++p)
|
|
*p = char(std::tolower(*p));
|
|
switch (t[0]) { // already checked that t isn't empty
|
|
case 'f':
|
|
if (t == "f" || t == "false") return false;
|
|
break;
|
|
case 'n':
|
|
if (t == "n" || t == "nil" || t == "no") return false;
|
|
break;
|
|
case 'o':
|
|
if (t == "off") return false;
|
|
else if (t == "on") return true;
|
|
break;
|
|
case 't':
|
|
if (t == "t" || t == "true") return true;
|
|
break;
|
|
case 'y':
|
|
if (t == "y" || t == "yes") return true;
|
|
break;
|
|
default:
|
|
break;
|
|
}
|
|
throw GeographicErr("Cannot decode " + t + " as a bool");
|
|
}
|
|
|
|
/**
|
|
* Convert a Math::real object to a string.
|
|
*
|
|
* @param[in] x the value to be converted.
|
|
* @param[in] p the precision used (default −1).
|
|
* @exception std::bad_alloc if memory for the string can't be allocated.
|
|
* @return the string representation.
|
|
*
|
|
* If \e p ≥ 0, then the number fixed format is used with p bits of
|
|
* precision. With p < 0, there is no manipulation of the format. This is
|
|
* an overload of str<T> which deals with inf and nan.
|
|
**********************************************************************/
|
|
template<> inline std::string Utility::str<Math::real>(Math::real x, int p) {
|
|
using std::isfinite;
|
|
if (!isfinite(x))
|
|
return x < 0 ? std::string("-inf") :
|
|
(x > 0 ? std::string("inf") : std::string("nan"));
|
|
std::ostringstream s;
|
|
#if GEOGRAPHICLIB_PRECISION == 4
|
|
// boost-quadmath treats precision == 0 as "use as many digits as
|
|
// necessary" (see https://svn.boost.org/trac/boost/ticket/10103 and
|
|
// https://github.com/boostorg/multiprecision/issues/416)
|
|
// Fixed by https://github.com/boostorg/multiprecision/pull/389
|
|
if (p == 0) {
|
|
using std::signbit; using std::fabs;
|
|
using std::round; using std::fmod;
|
|
int n = signbit(x) ? -1 : 1; x = fabs(x);
|
|
Math::real ix = round(x); // Rounds ties away from zero (up for positive)
|
|
// Implement the "round ties to even" rule
|
|
if (2 * (ix - x) == 1 && fmod(ix, Math::real(2)) == 1) --ix;
|
|
s << std::fixed << std::setprecision(1) << n*ix;
|
|
std::string r(s.str());
|
|
// strip off trailing ".0"
|
|
return r.substr(0, (std::max)(int(r.size()) - 2, 0));
|
|
}
|
|
#endif
|
|
if (p >= 0) s << std::fixed << std::setprecision(p);
|
|
s << x; return s.str();
|
|
}
|
|
|
|
} // namespace GeographicLib
|
|
|
|
#if defined(_MSC_VER)
|
|
# pragma warning (pop)
|
|
#endif
|
|
|
|
#endif // GEOGRAPHICLIB_UTILITY_HPP
|