std::basic_stringstream<CharT,Traits,Allocator>::basic_stringstream
From cppreference.com
< cpp | io | basic stringstream
basic_stringstream() : basic_stringstream(ios_base::in|ios_base::out) { } |
(1) | (since C++11) |
(2) | ||
explicit basic_stringstream( ios_base::openmode mode = ios_base::in|ios_base::out ); |
(until C++11) | |
explicit basic_stringstream( ios_base::openmode mode ); |
(since C++11) | |
explicit basic_stringstream( const std::basic_string<CharT,Traits,Allocator>& str, ios_base::openmode mode = ios_base::in|ios_base::out ); |
(3) | |
basic_stringstream( basic_stringstream&& other ); |
(4) | (since C++11) |
Constructs new string stream.
1) Default constructor. Constructs new underlying string device with the default open mode
2) Constructs new underlying string device. The underlying
basic_stringbuf
object is constructed as basic_stringbuf<Char,Traits,Allocator>(mode).3) Uses a copy of
str
as initial contents of the underlying string device. The underlying basic_stringbuf
object is constructed as basic_stringbuf<Char,Traits,Allocator>(str, mode).4) Move constructor. Constructs the string stream with the state of
other
using move semantics. Parameters
str | - | string to use as initial contents of the string stream | ||||||||||||||
mode | - | specifies stream open mode. It is bitmask type, the following constants are defined:
| ||||||||||||||
other | - | another string stream to use as source |
Notes
Construction of one-off basic_stringstream
objects in a tight loop, such as when used for string conversion, may be significantly more costly than calling str to reuse the same object.
Defect reports
The following behavior-changing defect reports were applied retroactively to previously published C++ standards.
DR | Applied to | Behavior as published | Correct behavior |
---|---|---|---|
P0935R0 | C++11 | default constructor was explicit | made implicit |
Example
Run this code
#include <iostream> #include <sstream> int main() { // default constructor (input/output stream) std::stringstream buf1; buf1 << 7; int n = 0; buf1 >> n; std::cout << "buf1 = " << buf1.str() << " n = " << n << '\n'; // input stream std::istringstream inbuf("-10"); inbuf >> n; std::cout << "n = " << n << '\n'; // output stream in append mode (C++11) std::ostringstream buf2("test", std::ios_base::ate); buf2 << '1'; std::cout << buf2.str() << '\n'; }
Output:
buf1 = 7 n = 7 n = -10 test1
See also
gets or sets the contents of underlying string device object (public member function) | |
constructs a basic_stringbuf object (public member function of std::basic_stringbuf<CharT,Traits,Allocator> ) |