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std::basic_..._view::data(3) C++ Standard Libary std::basic_..._view::data(3) NAME std::basic_string_view::data - std::basic_string_view::data Synopsis constexpr const_pointer data() const noexcept; (since C++17) Returns a pointer to the underlying character array. The pointer is such that the range [data(), data() + size()) is valid and the values in it corre- spond to the values of the view. Parameters (none) Return value A pointer to the underlying character array. Complexity Constant. Notes Unlike std::basic_string::data() and string literals, std::ba- sic_string_view::data() returns a pointer to a buffer that is not necessarily null-termi- nated, for example a substring view (e.g. from remove_suffix). Therefore, it is typically a mistake to pass data() to a routine that takes just a const CharT* and expects a null-terminated string. Example // Run this code #include <cstring> #include <cwchar> #include <iostream> #include <string> #include <string_view> int main() { std::wstring_view wcstr_v = L"xyzzy"; std::cout << std::wcslen(wcstr_v.data()) << '\n'; // OK: the underlying character array is null-terminated char array[3] = {'B', 'a', 'r'}; std::string_view array_v(array, sizeof array); // std::cout << std::strlen(array_v.data()) << '\n'; // error: the underlying character array is not null-terminated std::string str(array_v.data(), array_v.size()); // OK std::cout << std::strlen(str.data()) << '\n'; // OK: the underlying character array of a std::string is always null-terminated } Output: 5 3 See also front accesses the first character (public member function) back accesses the last character (public member function) data returns a pointer to the first character of a string (public member function of std::basic_string<CharT,Traits,Al- locator>) http://cppreference.com 2024.06.10 std::basic_..._view::data(3)
NAME | Synopsis | Parameters | Return value | Complexity | Notes | Example | Output: | See also
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