std::basic_string::operator basic_string_view
From cppreference.com
< cpp | string | basic string
| operator std::basic_string_view<CharT, Traits>() const noexcept; |
(since C++17) | |
Returns a std::basic_string_view, constructed as if by std::basic_string_view<CharT, Traits>(data(), size())
Parameters
(none)
Return value
A string view representing the entire contents of the string.
Example
Run this code
#include <iostream> #include <string> #include <string_view> void show_wstring_size(std::wstring_view wcstr_v) { std::cout << wcstr_v.size() << " code points\n"; } int main() { std::string cppstr = "ラーメン"; // narrow string std::wstring wcstr = L"ラーメン"; // wide string // Implicit conversion from string to string_view // via std::string::operator string_view: std::string_view cppstr_v = cppstr; std::cout << cppstr_v << '\n' << cppstr_v.size() << " code units\n"; // Implicit conversion from wstring to wstring_view // via std::wstring::operator wstring_view: show_wstring_size(wcstr); // Warning: // It is the programmer's responsibility to ensure that std::string_view // does not outlive the pointed-to string! std::string_view BAD(std::string("a temporary string")); // holds a dangling pointer! }
Output:
ラーメン 12 code units 4 code points
See also
constructs a basic_string_view (public member function of std::basic_string_view) |