CODEWITHSUNDEEP
c++stringgcccompilationprintf
Jan Schultke
Jan Schultke

Reputation: 39774

Why does GCC implement std::to_string using std::vsnprintf?

Recently, I looked into GCC's basic_string.h and noticed that all std::to_string overloads are implemented using std::vsnprintf like for example:

inline string
to_string(int __val)
{
    return __gnu_cxx::__to_xstring<string>(&std::vsnprintf, 4 * sizeof(int), "%d", __val);
}

Wouldn't this introduce a lot of overhead? Stringifying an integer base 10 is possible in just a few lines of code, so why would this be implemented using vsnprintf?

Upvotes: 0

Views: 351

Answers (1)

dewaffled
dewaffled

Reputation: 2983

This looked good enough considering they had lots of other stuff to implement for C++ 11.

They optimized it recently with gcc 10 release.

Upvotes: 2

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