C++: what is the optimal way to convert a double to a string?

Question

What is the most optimal way to achieve the same as this?

void foo(double floatValue, char* stringResult)
{
    sprintf(stringResult, \"%f\", floatV         


        

Answer 1

In the future, you can use std::to_chars to write code like https://godbolt.org/z/cEO4Sd . Unfortunately, only VS2017 and VS2019 support part of this functionality...

#include 
#include 
#include 
#include 
#include 

int main()
{
    std::array chars;
    auto [parsed, error] = std::to_chars(
        chars.data(), 
        chars.data() + chars.size(), 
        static_cast(12345.234)
    );
    std::cout << std::string_view(chars.data(), parsed - chars.data());
}

For a lengthy discussion on MSVC details, see https://www.reddit.com/r/cpp/comments/a2mpaj/how_to_use_the_newest_c_string_conversion/eazo82q/