std::basic_istringstream<CharT,Traits,Allocator>::basic_istringstream
(1) | ||
explicit basic_istringstream( std::ios_base::openmode mode = std::ios_base::in ); |
(until C++11) | |
explicit basic_istringstream( std::ios_base::openmode mode ); |
(since C++11) | |
basic_istringstream() : basic_istringstream(std::ios_base::in) {} |
(2) | (since C++11) |
explicit basic_istringstream ( const std::basic_string<CharT, Traits, Allocator>& str, |
(3) | |
explicit basic_istringstream ( std::basic_string<CharT, Traits, Allocator>&& str, |
(4) | (since C++20) |
basic_istringstream( std::ios_base::openmode mode, const Allocator& a ); |
(5) | (since C++20) |
template< class SAlloc > basic_istringstream( const std::basic_string<CharT, Traits, SAlloc>& str, |
(6) | (since C++20) |
template< class SAlloc > basic_istringstream( const std::basic_string<CharT, Traits, SAlloc>& str, |
(7) | (since C++20) |
template< class SAlloc > explicit basic_istringstream |
(8) | (since C++20) |
template< class StringViewLike > explicit basic_istringstream |
(9) | (since C++26) |
template< class StringViewLike > basic_istringstream( const StringViewLike& t, |
(10) | (since C++26) |
template< class StringViewLike > basic_istringstream( const StringViewLike& t, const Allocator& a ); |
(11) | (since C++26) |
basic_istringstream( basic_istringstream&& other ); |
(12) | (since C++11) |
Constructs new string stream.
Given
-
base_type
as std::basic_istream<CharT, Traits>, and -
buf_type
as std::basic_stringbuf<CharT, Traits, Allocator>,
the std::basic_istream base and the exposition-only data member sb
are initialized as follows.
Over load |
std::basic_istream base | sb
|
---|---|---|
(1) | base_type(std::addressof(sb))[1] | buf_type(mode | std::ios_base::in) |
(2) | buf_type(std::ios_base::in) | |
(3) | buf_type(str, mode | std::ios_base::in) | |
(4) | buf_type(std::move(str), mode | std::ios_base::in) | |
(5) | buf_type(mode | std::ios_base::in, a) | |
(6) | buf_type(str, mode | std::ios_base::in, a) | |
(7) | buf_type(str, std::ios_base::in, a) | |
(8) | buf_type(str, mode | std::ios_base::in) | |
(9) | std::addressof(sb) | {t, mode | std::ios_base::in, Allocator()} |
(10) | {t, mode | std::ios_base::in, a} | |
(11) | {t, std::ios_base::in, a} | |
(12) | move constructed from other's std::basic_istream base | move constructed from other.sb |
- ↑ The std::basic_iostream base was intialized with base_type(&sb) (for overloads (1,3)) until C++11.
Contents |
[edit] Parameters
str | - | string to use as initial contents of the string stream | ||||||||||||||||
t | - | an object (convertible to std::basic_string_view) to use as initial contents of the string stream | ||||||||||||||||
a | - | allocator used for allocating the contents of the string stream | ||||||||||||||||
mode | - | specifies stream open mode. It is a BitmaskType, the following constants are defined:
| ||||||||||||||||
other | - | another string stream to use as source |
[edit] Notes
Construction of one-off basic_istringstream
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.
Feature-test macro | Value | Std | Feature |
---|---|---|---|
__cpp_lib_sstream_from_string_view |
202306L |
(C++26) | Interfacing std::stringstreams with std::string_view, (9-11) |
[edit] Example
#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
[edit] 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 | the default constructor was explicit | made implicit |
[edit] 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> )
|