std::basic_string_view<CharT,Traits>:: empty
From cppreference.com
<
cpp
|
string
|
basic string view
|
constexpr
bool
empty
(
)
const
noexcept
;
|
(since C++17) | |
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
|
returns the number of characters
(public member function) |
|
|
returns the maximum number of characters
(public member function) |
|
|
(C++17)
(C++20)
|
returns the size of a container or array
(function template) |
|
(C++17)
|
checks whether the container is empty
(function template) |
|
checks whether the string is empty
(public member function of
std::basic_string<CharT,Traits,Allocator>
)
|