std::ispunct(std::locale)(3)

📦 version 2024.07.05, in nixpkgs unstable, opensuse-leap 16.0

💅 std::ispunct(std::locale)(3) 💅

Okay bestie, welcome to the C++ Standard Libary manual, section 3 — yes, that's the manual name, typo and all, no cap. Today's main character is the locale-aware punctuation check: std::ispunct(std::locale). It's giving “does this character count as punctuation in this locale?” energy, and honestly? Iconic. 🎀

🌸 NAME 🌸

std::ispunct(std::locale) — std::ispunct(std::locale). That's the name, bestie. It's the locale-flavored punctuation checker. Periodt. 💖

✨ Synopsis ✨

Defined in header <locale>:

template< class CharT >
bool ispunct( CharT ch, const locale& loc );

So what's the vibe check? It checks if the given character is classified as a punctuation character by the given locale's std::ctype facet. That's the whole assignment. 🦋

🎀 Parameters 🎀

  • ch — character
  • loc — locale

💖 Return value 💖

Returns true if the character is classified as punctuation, false otherwise. Simple as that, bestie. ✨

🧚 Possible implementation 🧚

Here's how it could look under the hood, fr fr:

template<class CharT>
bool ispunct(CharT ch, const std::locale& loc)
{
    return
        std::use_facet<std::ctype<CharT>>(loc).is(std::ctype_base::punct, ch);
}

🌈 Example 🌈

This one demonstrates the use of std::ispunct() with different locales (OS-specific). So yes, your mileage may vary depending on the OS, bestie — it's not me being dramatic, that's literally in the notes. 🙈

// Run this code

#include <iostream>
#include <locale>

int main()
{
    const wchar_t c = L'\u214b'; // upside-down ampersand

    std::locale loc1("C");
    std::cout << "ispunct('⅋', C locale) returned "
              << std::boolalpha << std::ispunct(c, loc1) << '\n';

    std::locale loc2("en_US.UTF-8");
    std::cout << "ispunct('⅋', Unicode locale) returned "
              << std::boolalpha << std::ispunct(c, loc2) << '\n';
}

🍓 Possible output 🍓

isalpha('⅋', C locale) returned false
isalpha('⅋', Unicode locale) returned true

Yes, the output says isalpha while the example calls ispunct — I'm not fixing it, I'm preserving it. The lore is the lore. 💀

👑 See also 👑

  • ispunct — checks if a character is a punctuation character (function)
  • iswpunct — checks if a wide character is a punctuation character (function)

Source/version/date sign-off, bestie: http://cppreference.com · 2024.06.10 · page std::ispunct(std::locale)(3) 💜✨

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