std::basic_string<CharT,Traits,Allocator>::data
(constexpr since C++20)
(constexpr since C++20)
Returns a pointer to the underlying array serving as character storage. The pointer is such that the range
[data(), data() + size())
[data(), data() + size()]
is valid and the values in it correspond to the values stored in the string.
The returned array is not required to be null-terminated.
If empty() returns true, the pointer is a non-null pointer that should not be dereferenced.
(until C++11)The returned array is null-terminated, that is, data() and c_str() perform the same function.
If empty() returns true, the pointer points to a single null character.
(since C++11)The pointer obtained from data() may be invalidated by:
- Passing a non-const reference to the string to any standard library function, or
- Calling non-const member functions on the string, excluding
operator[](), at() , front() , back() , begin() , end() , rbegin() , rend() .
data has undefined behavior.data() + size() to any value other than CharT() has undefined behavior.[edit] Parameters
(none)
[edit] Return value
A pointer to the underlying character storage.
data()[i] == operator[](i) for every i in [0, size()).
data() + i == std::addressof (operator[](i)) for every i in [0, size()].
[edit] Complexity
Constant.
[edit] Example
#include <algorithm> #include <cassert> #include <cstring> #include <string> int main() { std::string const s("Emplary"); assert (s.size() == std::strlen (s.data())); assert (std::equal (s.begin(), s.end(), s.data())); assert (std::equal (s.data(), s.data() + s.size(), s.begin())); assert ('0円' == *(s.data() + s.size())); }
[edit] See also
(public member function) [edit]