The ‘=’ is an operator in C++ STL which copies (or moves) a set to another set and set::operator= is the corresponding operator function. There are three versions of this function:
- The first version takes reference of an set as an argument and copies it to an set.
Syntax:
ums1.operator=(set &set2)
Parameters: The first version takes the reference of an set as argument.
- The second version performs a move assignment i.e it moves the content of an set to another set.
Syntax:
ums1.operator=(set &&set2)
Parameters: The second version takes the r-value reference of an set as argument
- The third version assigns contents of an initializer list to an set.
Syntax:
ums1.operator=(initializer list)
Parameters: The third version takes an initializer list as argument.
Return Value: All of them return the value of this pointer(*this).
The following programs illustrates set::operator= :
// C++ code to illustrate the method // set::operator=() #include <iostream> #include <set> using namespace std; // merge function template < class T> T merge(T a, T b) { T t(a); t.insert(b.begin(), b.end()); return t; } int main() { set< int > sample1, sample2, sample3; // List initialization sample1 = { 1, 2, 3, 4, 5 }; sample2 = { 6, 7, 8, 1 }; // Merge both sets and // move the result to sample3 sample3 = merge(sample1, sample2); // copy assignment sample1 = sample3; // Print the sets for ( auto it = sample1.begin(); it != sample1.end(); ++it) { cout << *it << " " ; } cout << endl; for ( auto it = sample2.begin(); it != sample2.end(); ++it) { cout << *it << " " ; } cout << endl; for ( auto it = sample3.begin(); it != sample3.end(); ++it) { cout << *it << " " ; } cout << endl; return 0; } |
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