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std::basic_..._view::empty(3) C++ Standard Libarystd::basic_..._view::empty(3) NAME std::basic_string_view::empty - std::basic_string_view::empty Synopsis constexpr bool empty() const noexcept; (since C++17) (until C++20) [[nodiscard]] constexpr bool empty() const noexcept; (since C++20) Checks if the view has no characters, i.e. whether size() == 0. Parameters (none) Return value true if the view is empty, false otherwise. Complexity Constant. Example // Run this code #include <iostream> #include <string_view> // Print a string surrounded by single quotes, its // length and whether it is considered empty. void check_string(std::string_view ref) { std::cout << std::boolalpha << "'" << ref << "' has " << ref.size() << " character(s); emptiness: " << ref.empty() << '\n'; } int main(int argc, char **argv) { // An empty string check_string(""); // Almost always not empty: argv[0] if (argc > 0) check_string(argv[0]); } Possible output: '' has 0 character(s); emptiness: true './a.out' has 7 character(s); emptiness: false See also size returns the number of characters length (public member function) max_size returns the maximum number of characters (public member function) size ssize returns the size of a container or array (C++17) (function template) (C++20) empty checks whether the container is empty (C++17) (function template) checks whether the string is empty empty (public member function of std::ba- sic_string<CharT,Traits,Allocator>) http://cppreference.com 2024.06.10 std::basic_..._view::empty(3)
NAME | Synopsis | Parameters | Return value | Complexity | Example | Possible output: | See also
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