std::ostrstream::ostrstream
From cppreference.com
< cpp | io | ostrstream
ostrstream(); |
(1) | (deprecated in C++98) (removed in C++26) |
|
ostrstream(
char
* s, int n, std::ios_base::openmode mode =
std::ios_base::out
)
;
|
(2) | (deprecated in C++98) (removed in C++26) |
Constructs new output strstream and its underlying std::strstreambuf.
1) Default-constructs the underlying std::strstreambuf, which creates a dynamically growing buffer, and initializes the base class with the address of the
strstreambuf
2) Initialized the base class with the address of the underlying std::strstreambuf
a) if the
app bit is not set in mode, constructs the buffer by calling strstreambuf(s, n, s). The behavior is undefined if there are less than n elements in the array whose first element is pointed to by s
b) if the
app bit is set in mode, constructs the buffer by calling
strstreambuf(s, n, s +
std::strlen
(s)
)
. The behavior is undefined if there are less than n elements in the array whose first element is pointed to by s
Parameters
| s | - | char array to use as the output buffer | ||||||||||||||||
| n | - | size of the array to be used as the output buffer | ||||||||||||||||
| mode | - | specifies stream open mode. It is a bitmask type, the following constants are defined (although only app is used):
|
Example
Run this code
#include <iostream> #include <strstream> int main() { std::ostrstream s1; // dynamic buffer s1 << 1 << ' ' << 3.14 << " example\n" << std::ends; std::cout << s1.str(); s1.freeze(false); char arr[15] = "Hello"; std::ostrstream s2(arr, sizeof arr, std::ios_base::app); s2 << ", world!" << std::ends; std::cout << s2.str() << '\n'; std::cout << arr << '\n'; // streams use the provided arrays }
Output:
1 3.14 example Hello, world! Hello, world!
See also
constructs a strstreambuf object (public member function of std::strstreambuf) |
|
constructs an istrstream object, optionally allocating the buffer (public member function of std::istrstream) |
|
constructs a strstream object, optionally allocating the buffer (public member function of std::strstream) |