to_static_string: like std::to_string, but without surprises

This is a tiny, header-only library that implements to_static_string: a C++17 drop-in replacement for std::to_string, based on std::to_chars.

For instance:

#include "tostr/to_static_string.h"
#include <iostream>

int main()
{
    // We have an integer value to convert to string
    int value = 42;

    // Converting it returns a cstatic_string<N>, a stack-based
    // string holding the result of the conversion. N is selected
    // at compile-time, depending on the type
    auto str = tostr::to_static_string(value);

    // We can use .get() to retrieve a std::string_view for that buffer
    std::cout << "The answer is: " << str.get() << std::endl;
}

Comparison

When compared to std::to_string, it has the following advantages:

• It is faster. See the benchmark section (TODO: link) below.
• It is non-allocating. All operations use stack memory.
• It is non-throwing. It is guaranteed that to_static_string will never throw exceptions.
• It is locale-independant. This is specially important for floating-point values, where the decimal point can be affected by locale configuration.

When compared to just using std::to_chars:

• It is a level of abstraction above. This means it is safer, since you do not need to think of buffer size - we do it for you.
• It has comparable performance (see below).

Banchmarks

These benchmarks have been obtained under an i7-10510U CPU @ 1.80GHz, using clang-18, under CMake Release variant, using libstdc++ (Ubuntu 22.04) and C++20.

Tested under

Testing is still an ongoing effort. It has only been tested locally with the compiler/setup mentioned above.

Benchmark

Benchmark	Time	Iterations
std::to_string(long)	45.3 ns	11844179
to_static_string(long)	27.7 ns	30023151
std::to_chars(char*, char*, long)	27.4 ns	25507148
std::to_string(double)	1245 ns	480956
to_static_string(double)	95.6 ns	6366312
std::to_chars(char*, char*, double)	98.4 ns	7338231