C++: Converting a double/float to string, preserve scientific notation and precision

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不思量自难忘°
不思量自难忘° 2021-01-27 11:46

I\'m trying to convert double/float numbers to string. Some of these numbers contain scientific notation \"e\", and I want to preserve it after the conversion. I searched throug

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  •  -上瘾入骨i
    2021-01-27 12:38

    Two things:

    Fixed isn't what you want if you want scientific notation. It's the opposite.

    when I compile

    #include 
    #include 
    
    template 
    inline std::string ToString(T value) {
        std::stringstream out;
        out << std::fixed;  
        out << value;
        return out.str();
    }
    int main()  
    {
        double mydouble = 1.7976931348623157e+308; 
        std::cout << ToString(mydouble) << std::endl; 
    }
    

    I get

    179769313486231570814527423731704356798070567525844996598917476803157260780028538760589558632766878171540458953514382464234321326889464182768467546703537516986049910576551282076245490090389328944075868508455133942304583236903222948165808559332123348274797826204144723168738177180919299881250404026184124858368.000000
    

    which is right, which means there's a bug in your C++ compiler or standard library.

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