std::from_chars doens't compile under MSVC

问题

I have a little function that uses std::from_chars to create a date object from a std::string_view, while it compiles using clang or gcc under ubuntu it doesn't using msvc under windows.

date::year_month_day parseDate(const std::string_view& s)
{
    int y { 0 }, m { 0 }, d { 0 };

    std::from_chars(s.begin(), s.begin() + 4, y);
    std::from_chars(s.begin() + 5, s.begin() + 7, m);
    std::from_chars(s.begin() + 8, s.begin() + 10, d);

    return date::year { y } / m / d;
}

For each of std::from_chars call the following error is displayed at compile time:

'std::from_chars': none of the 14 overloads could convert all the argument types

The compiler then proceeds to make a list of possible overloads and i clearly see the one that I'm trying to use:

'std::from_chars_result std::from_chars(const char *const ,const char *const ,int &,const int) noexcept'

The last parameter has a default value. Can someone explain me what I'm doing wrong?

回答1:

As mentioned by Some programmer dude and Ruks, std::string_view.begin() doesn't return a const char *const, std::string_view.data() was the method i was looking for.

来源：https://stackoverflow.com/questions/61203317/stdfrom-chars-doenst-compile-under-msvc