Assignment operators

Template:cpp/language/sidebar Assignment operators modify the value of the object.

Operator name	Syntax	Over​load​able	Prototype examples (for Template:cpp)
			Inside class definition	Outside class definition
basic assignment	a = b	Yes	Template:cpp	N/A
move assignment Template:mark c++0x	a = rvalue	Yes	Template:cpp	N/A
addition assignment	a += b	Yes	Template:cpp	Template:cpp
subtraction assignment	a -= b	Yes	Template:cpp	Template:cpp
multiplication assignment	a *= b	Yes	Template:cpp	Template:cpp
division assignment	a /= b	Yes	Template:cpp	Template:cpp
modulo assignment	a %= b	Yes	Template:cpp	Template:cpp
bitwise AND assignment	a &= b	Yes	Template:cpp	Template:cpp
bitwise OR assignment	a |= b	Yes	Template:cpp	Template:cpp
bitwise XOR assignment	a ^= b	Yes	Template:cpp	Template:cpp
bitwise left shift assignment	a <<= b	Yes	Template:cpp	Template:cpp
bitwise right shift assignment	a >>= b	Yes	Template:cpp	Template:cpp
Notes All operators usually return *this. However, essentially any value and any type can be returned (including Template:cpp, i.e. no return value), yet this is unintuitive and defeats the purpose of the operators. T2 can be any type including T

Explanation

basic assignment operator replaces the contents of the object a with those of b

move assignment operator replaces the contents of the object a with those of b while minimizing copying overhead (no deep copy is performed). It complements the basic assignment operator.

Other assignment operators modify the contents of the object. Usually they are overloaded in classed performing mathematical operations.

See also

Operator precedence

Common operators
assignment	increment decrement	arithmetic	logical	comparison	member access	other
a = b a += b a -= b a *= b a /= b a %= b a &= b a |= b a ^= b a <<= b a >>= b	++a --a a++ a--	+a -a a + b a - b a * b a / b a % b ~a a & b a | b a ^ b a << b a >> b	!a a && b a || b	a == b a != b a < b a > b a <= b a >= b a <=> b	a[...] *a &a a->b a.b a->*b a.*b	function call
						a(...)
						comma
						a, b
						conditional
						a ? b : c
Special operators
static_cast converts one type to another related type dynamic_cast converts within inheritance hierarchies const_cast adds or removes cv-qualifiers reinterpret_cast converts type to unrelated type C-style cast converts one type to another by a mix of static_cast, const_cast, and reinterpret_cast new creates objects with dynamic storage duration delete destructs objects previously created by the new expression and releases obtained memory area sizeof queries the size of a type sizeof... queries the size of a parameter pack (since C++11) typeid queries the type information of a type noexcept checks if an expression can throw an exception (since C++11) alignof queries alignment requirements of a type (since C++11)