Defined in header
Function object for performing comparisons. The parameter types of the function call operator (but not the return type) are deduced from the arguments.
 Member types
||/* unspecified */|
 Member functions
| checks if the arguments are equal |
(public member function)
template< class T, class U >
requires std::equality_comparable_with<T, U> ||
When a call would invoke a built-in operator comparing pointers of type
P, the result is instead determined as follows:
- Returns false if one of the (possibly converted) value of the first argument and the (possibly converted) value of the second argument precedes the other in the implementation-defined strict total ordering over all pointer values of type
P. This strict total ordering is consistent with the partial order imposed by the builtin operators
- Otherwise (neither precedes the other), returns true.
The behavior is undefined unless the the conversion sequences from both
P are equality-preserving (see below).
 Equality preservation
An expression is equality preserving if it results in equal outputs given equal inputs.
- The inputs to an expression consist of its operands.
- The outputs of an expression consist of its result and all operands modified by the expression (if any).
In specification of standard concepts, operands are defined as the largest subexpressions that include only:
The cv-qualification and value category of each operand is determined by assuming that each template type parameter denotes a cv-unqualified complete non-array object type.
Every expression required to be equality preserving is further required to be stable: two evaluations of such an expression with the same input objects must have equal outputs absent any explicit intervening modification of those input objects.
std::ranges::equal_to requires both
!= to be valid (via the equality_comparable_with constraint).
|This section is incomplete|
Reason: no example
 See also
| function object implementing x == y |