std::litera...operator""sv(3)

💖 NAME 💖

Okay so welcome to the page for std::litera...operator""sv(3) from the C++ Standard Libary manual. The actual thing this page is about is std::literals::string_view_literals::operator""sv — and yes, the NAME section lists it twice, both as std::literals::string_view_literals::operator""sv, so we’re keeping both because that’s the lore. No cap. 💅

✨ Synopsis ✨

Here’s the synopsis exactly as written, weird line wraps and all:

          Defined in header <string_view>
          constexpr std::string_view
       (1) (since C++17)
              operator ""sv( const char* str, std::size_t len ) noexcept;
          constexpr std::u8string_view
       (2) (since C++20)
              operator ""sv( const char8_t* str, std::size_t len ) noexcept;
          constexpr std::u16string_view
              operator ""sv( const char16_t* str, std::size_t len )
       (3) (since C++17)
          noexcept;
          constexpr std::u32string_view
              operator ""sv( const char32_t* str, std::size_t len )
       (4) (since C++17)
          noexcept;
          constexpr std::wstring_view
       (5) (since C++17)
              operator ""sv( const wchar_t* str, std::size_t len ) noexcept;

Forms a string view of a character literal. Literally its whole job. 🫶

1. Returns std::string_view{str, len}.
2. Returns std::u8string_view{str, len}.
3. Returns std::u16string_view{str, len}.
4. Returns std::u32string_view{str, len}.
5. Returns std::wstring_view{str, len}.

🦋 Parameters 🦋

• str — pointer to the beginning of the raw character array literal
• len — length of the raw character array literal

🌸 Return value 🌸

The std::basic_string_view literal. That’s the vibe. ✨

🎀 Notes 🎀

These operators are declared in the namespace std::literals::string_view_literals, where both literals and string_view_literals are inline namespaces. Access to these operators can be gained with any of:

• using namespace std::literals,
• using namespace std::string_view_literals, or
• using namespace std::literals::string_view_literals.

🔥 Example 🔥

// Run this code

#include <iostream>
#include <string_view>
#include <typeinfo>

void print_each_character(const std::string_view sw)
{
    for (char c : sw)
        std::cout << (c == '\0' ? '@' : c);
    std::cout << '\n';
}

int main()
{
    using namespace std::literals;

    std::string_view s1 = "abc\0\0def";
    std::string_view s2 = "abc\0\0def"sv;

    std::cout << "s1.size(): " << s1.size() << "; s1: ";
    print_each_character(s1);
    std::cout << "s2.size(): " << s2.size() << "; s2: ";
    print_each_character(s2);

    std::cout << "substr(1, 4): " << "abcdef"sv.substr(1, 4) << '\n';

    auto value_type_info = []<typename T>(T)
    {
        using V = typename T::value_type;
        std::cout << "sizeof " << typeid(V).name() << ": " << sizeof(V)
       << '\n';
    };

    value_type_info("char A"sv);
    value_type_info(L"wchar_t ∀"sv);
    value_type_info(u8"char8_t ∆"sv);
    value_type_info(u"char16_t ∇"sv);
    value_type_info(U"char32_t ∃"sv);
    value_type_info(LR"(raw ⊞)"sv);
}

🌈 Possible output 🌈

s1.size(): 3; s1: abc
s2.size(): 8; s2: abc@@def
substr(1, 4): bcde
sizeof char: 1
sizeof wchar_t: 4
sizeof char8_t: 1
sizeof char16_t: 2
sizeof char32_t: 4
sizeof wchar_t: 4

👑 See also 👑

• constructor — constructs a basic_string_view (public member function)
• operator""s — converts a character array literal to basic_string (C++14) (function)

Source/version/date sign-off bestie: this page is from http://cppreference.com, dated 2024.06.10, with footer title std::litera...operator""sv(3). Go forth and string-view slay 💖✨