public member function
<ios> <iostream>

std::basic_ios::copyfmt

basic_ios& copyfmt (const basic_ios& rhs);
Copy formatting information
Copies the values of all the internal members of rhs (except the state flags and the associated stream buffer) to the corresponding members of *this.

After the call, the following member functions return the same for rhs and *this:
elementdescription
flagsformat flags
widthfield width
precisionprecision
getlocselected locale
iarrayinternal extensible array *
parrayinternal extensible array *
fillfill character
tietied stream
exceptionsexceptions mask (last to be copied, see below)

* Each stream object keeps its own copy of the internal extensible array (iword, pword): Its contents are copied, not just a pointer to it.
* Each stream object keeps its own copy of the internal extensible array (iword, pword): Its contents are copied, not just a pointer to it.

If any of the pointer values to be copied points to objects stored outside rhs and those objects are destroyed when rhs is destroyed, *this stores instead pointers to newly constructed copies of these objects.

Calling this function invokes all functions registered through member register_callback twice: First, before the copying process starts, the function calls each registered callback fn using (*fn)(erase_event,*this,index). Then, at the end, right before the exceptions mask is copied, the function calls each registered callback fn wirh (*fn)(copyfmt_event,*this,index) (this second round can be used, for example, to access and modify the copied internal extensible array).

Parameters

rhs
Stream object whose members are copied to *this.

Return Value

*this

Example

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// copying formatting information
#include <iostream>     // std::cout
#include <fstream>      // std::ofstream

int main () {
  std::ofstream filestr;
  filestr.open ("test.txt");

  std::cout.fill ('*');
  std::cout.width (10);
  filestr.copyfmt (std::cout);

  std::cout << 40;
  filestr << 40;

  return 0;
}

This example outputs a number formatted in the same way to both cout and a file called "test.txt":
********40


Data races

Modifies the stream object (*this), and accesses rhs.
Concurrent access to any of the objects may cause data races.

Exception safety

Basic guarantee: if an exception is thrown, the stream is in a valid state.

See also