What is the difference between
MyClass mc = MyClass();
and
MyClass mc;
in C++?
What is the difference between MyClass mc = MyClass(); and MyClass mc; in C++?
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What is the difference between
MyClass mc = MyClass();
and
MyClass mc;
in C++?
The first invokes copy constructor, with temporary object as parameter –
MyClass()creates temporary.The second invokes default constructor.
In reality, they are, in most cases, optimized out to the same code, but that’s the semantical difference.
As Negal mentioned, the case is a bit different with POD types; when “MyClass” is POD, the second snippet will not value-initialize
mc, whereas first will.