std::basic_string_view<CharT,Traits>::operator[] - cppreference.com (original) (raw)
| constexpr const_reference operator[]( size_type pos ) const; | | (since C++17) | | ---------------------------------------------------------------- | | ------------- |
Returns a const reference to the character at specified location pos.
| If pos < size() is false, the behavior is undefined. | (until C++26) |
|---|---|
| If pos < size() is false: If the implementation is hardened, a contract violation occurs. Moreover, if the contract-violation handler returns under “observe” evaluation semantic, the behavior is undefined. If the implementation is not hardened, the behavior is undefined. | (since C++26) |
Contents
[edit] Parameters
| pos | - | position of the character to return |
|---|
[edit] Return value
_[data](../basic%5Fstring%5Fview.html#data "cpp/string/basic string view")_ [pos]
[edit] Exceptions
Does not throw.
[edit] Complexity
Constant.
[edit] Notes
Unlike std::basic_string::operator[], std::basic_string_view::operator[](size()) does not return a reference to CharT().
[edit] Example
#include #include int main() { std::string str = "Exemplar"; std::string_view v = str; std::cout << v[2] << '\n'; // v[2] = 'y'; // Error: cannot modify through a string view str[2] = 'y'; std::cout << v[2] << '\n'; }
Output:
[edit] See also
| | accesses the specified character with bounds checking (public member function) [edit] | | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | | accesses the specified character (public member function of std::basic_string<CharT,Traits,Allocator>) [edit] |