std::basic_stringstream<CharT,Traits,Allocator>::str
std::basic_string<CharT,Traits,Allocator> str() const; | (1) | |
void str(const std::basic_string<CharT,Traits,Allocator>& new_str); | (2) |
Manages the contents of the underlying string object.
1) Returns a copy of the underlying string as if by calling rdbuf()->str()
.
2) Replaces the contents of the underlying string as if by calling rdbuf()->str(new_str)
.
Parameters
new_str | - | new contents of the underlying string |
Return value
1) a copy of the underlying string object.
2) (none).
Notes
The copy of the underlying string returned by str
is a temporary object that will be destructed at the end of the expression, so directly calling c_str()
on the result of str()
(for example in auto *ptr = out.str().c_str();
) results in a dangling pointer.
Example
#include <sstream> #include <iostream> int main() { int n; std::istringstream in; // could also use in("1 2") in.str("1 2"); in >> n; std::cout << "after reading the first int from \"1 2\", the int is " << n << ", str() = \"" << in.str() << "\"\n"; std::ostringstream out("1 2"); out << 3; std::cout << "after writing the int '3' to output stream \"1 2\"" << ", str() = \"" << out.str() << "\"\n"; std::ostringstream ate("1 2", std::ios_base::ate); ate << 3; std::cout << "after writing the int '3' to append stream \"1 2\"" << ", str() = \"" << ate.str() << "\"\n"; }
Output:
after reading the first int from "1 2", the int is 1, str() = "1 2" after writing the int '3' to output stream "1 2", str() = "3 2" after writing the int '3' to append stream "1 2", str() = "1 23"
See also
replaces or obtains a copy of the associated character string (public member function of std::basic_stringbuf<CharT,Traits,Allocator> ) |
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