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std::basic_string_view<CharT,Traits>::front

From cppreference.com
 
C++
 
Strings library
 
std::basic_string_view
 
constexpr const_reference front() const;
 (since C++17)

Returns reference to the first character in the view.

If empty() is true, the behavior is undefined.

(until C++26)

If empty() is true:

  • 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] Return value

data_[0]

[edit] Complexity

Constant.

[edit] Example

Run this code
#include <iostream>
#include <string_view>
 
int main()
{
    for (std::string_view str{"ABCDEF"}; !str.empty(); str.remove_prefix(1))
        std::cout << str.front() << ' ' << str << '\n';
}

Output: 

A ABCDEF
B BCDEF
C CDEF
D DEF
E EF
F F

[edit] See also

 accesses the last character
(public member function) [edit]
checks whether the view is empty
(public member function) [edit]
(DR*)
 accesses the first character
(public member function of std::basic_string<CharT,Traits,Allocator>) [edit]
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