std::isspace(std::locale)(3)

💖 std::isspace(std::locale)(3) 💖

okay so bestie, welcome to the C++ Standard Libary manual, section 3 — yes that's how they spell it, don't come for me, i'm just the messenger 🎀 this page is literally all about std::isspace(std::locale) and it's giving "tiny function, big feelings."

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✨ NAME ✨

std::isspace(std::locale) — literally just std::isspace(std::locale), that's the whole name, she's not hiding anything 💅

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🌸 Synopsis 🌸

first things first, she lives in this header, no cap:

Defined in header <locale>

and here's her whole signature, character for character:

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

so what does she do?? she checks if the given character is classified as a whitespace character by the given locale's std::ctype facet 🦋 that's it, that's the vibe check.

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🎀 Parameters 🎀

• ch — the character. your lil guy. the one getting checked 👀
• loc — the locale. the whole cultural context deciding whether your character counts as space or not, iconic behavior honestly

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💜 Return value 💜

returns true if the character is classified as a whitespace character, and false otherwise ✨ simple! clean! no drama!

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🧚 Possible implementation 🧚

here's how she could be built under the hood, and honestly it's giving one-liner main character energy:

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

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🌈 Example 🌈

this one demonstrates std::isspace() with different locales, and heads up — it's OS-specific, so your mileage may absolutely vary 🫶

the page literally has a // Run this code button above this bad boy, that's the cppreference special

#include <iostream>
#include <locale>

void try_with(wchar_t c, const char* loc)
{
    std::wcout << "isspace('" << c << "', locale(\"" << loc << "\")) returned "
               << std::boolalpha << std::isspace(c, std::locale(loc)) << '\n';
}

int main()
{
    const wchar_t EM_SPACE = L'\u2003'; // Unicode character 'EM SPACE'
    try_with(EM_SPACE, "C");
    try_with(EM_SPACE, "en_US.UTF8");
}

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⭐ Possible output ⭐

look at this little glow-up between locales, we love to see it:

isspace(' ', locale("C")) returned false
isspace(' ', locale("en_US.UTF8")) returned true

like… the C locale said "not my problem" and en_US.UTF8 said "oh she's space space" 😭✨

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🦋 See also 🦋

• isspace — checks if a character is a space character (function) 👑
• iswspace — checks if a wide character is a space character (function) 💫

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okay that's the whole page, you're basically a locale expert now, no cap 💅✨

sign-off time bestie: this lil beauty lives over at http://cppreference.com, dated 2024.06.10, and she's filed under std::isspace(std::locale)(3) — mwah, go forth and check your whitespace 🍓🫶💖