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Enum member `std.traits.isAssignable`

Returns true iff a value of type Rhs can be assigned to a variable of type Lhs.


						
				enum isAssignable(Lhs, Rhs)
				 = isRvalueAssignable!(Lhs, Rhs) && isLvalueAssignable!(Lhs, Rhs);

isAssignable returns whether both an lvalue and rvalue can be assigned.

If you omit Rhs, isAssignable will check identity assignable of Lhs.

Example

static assert( isAssignable!(long, int));
static assert(!isAssignable!(int, long));
static assert( isAssignable!(const(char)[], string));
static assert(!isAssignable!(string, char[]));

// int is assignable to int
static assert( isAssignable!int);

// immutable int is not assignable to immutable int
static assert(!isAssignable!(immutable int));
}

/**
Returns `true` iff an rvalue of type `Rhs` can be assigned to a variable of
type `Lhs`.
*/
enum isRvalueAssignable(Lhs, Rhs = Lhs) = __traits(compiles, { lvalueOf!Lhs = rvalueOf!Rhs;

Authors

Walter Bright, Tomasz Stachowiak (isExpressions), Andrei Alexandrescu, Shin Fujishiro, Robert Clipsham, David Nadlinger, Kenji Hara, Shoichi Kato

License

Boost License 1.0.