conversion.h

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#ifndef CONVERSION_H_62B23520_7C8E_11DE_8A39_0800200C9A66
#define CONVERSION_H_62B23520_7C8E_11DE_8A39_0800200C9A66

#if defined(_MSC_VER) || (defined(__GNUC__) && (__GNUC__ == 3 && __GNUC_MINOR__ >= 4) || (__GNUC__ >= 4)) // GCC supports "pragma once" correctly since 3.4
#pragma once
#endif


#include "yaml-cpp-pm/null.h"
#include "yaml-cpp-pm/traits.h"
#include <limits>
#include <string>
#include <sstream>

namespace YAML_PM
{
        // traits for conversion
        
        template<typename T>
        struct is_scalar_convertible { enum { value = is_numeric<T>::value }; };
        
        template<> struct is_scalar_convertible<std::string> { enum { value = true }; };
        template<> struct is_scalar_convertible<bool> { enum { value = true }; };
        template<> struct is_scalar_convertible<_Null> { enum { value = true }; };

        // actual conversion
        
        inline bool Convert(const std::string& input, std::string& output) {
                output = input;
                return true;
        }
        
        YAML_CPP_API bool Convert(const std::string& input, bool& output);
        YAML_CPP_API bool Convert(const std::string& input, _Null& output);
        
        inline bool IsInfinity(const std::string& input) {
                return input == ".inf" || input == ".Inf" || input == ".INF" || input == "+.inf" || input == "+.Inf" || input == "+.INF";
        }
        
        inline bool IsNegativeInfinity(const std::string& input) {
                return input == "-.inf" || input == "-.Inf" || input == "-.INF";
        }
        
        inline bool IsNaN(const std::string& input) {
                return input == ".nan" || input == ".NaN" || input == ".NAN";
        }


        template <typename T> 
        inline bool Convert(const std::string& input, T& output, typename enable_if<is_numeric<T> >::type * = 0) {
                std::stringstream stream(input);
                stream.unsetf(std::ios::dec);
        if((stream >> output) && (stream >> std::ws).eof())
            return true;
                
                if(std::numeric_limits<T>::has_infinity) {
                        if(IsInfinity(input)) {
                                output = std::numeric_limits<T>::infinity();
                                return true;
                        } else if(IsNegativeInfinity(input)) {
                                output = -std::numeric_limits<T>::infinity();
                                return true;
                        }
                }
                
                if(std::numeric_limits<T>::has_quiet_NaN && IsNaN(input)) {
                        output = std::numeric_limits<T>::quiet_NaN();
                        return true;
                }
                
                return false;
        }
}

#endif // CONVERSION_H_62B23520_7C8E_11DE_8A39_0800200C9A66