stateSize

Returns the size in bytes of the state that needs to be allocated to hold an object of type T.

There is a difference between the .sizeof-property and $(D_PSYMBOL stateSize) if T is a class or an interface. T.sizeof is constant on the given architecture then and is the same as size_t.sizeof and ptrdiff_t.sizeof. This is because classes and interfaces are reference types and .sizeof returns the size of the reference which is the same as the size of a pointer. $(D_PSYMBOL stateSize) returns the size of the instance itself.

The size of a dynamic array is size_t.sizeof * 2 since a dynamic array stores its length and a data pointer. The size of the static arrays is calculated differently since they are value types. It is the array length multiplied by the element size.

stateSize!void is 1 since $(D_KEYWORD void) is mostly used as a synonym for $(D_KEYWORD byte)/$(D_KEYWORD ubyte) in void*.

template stateSize (

) {

static if(isPolymorphicType!T)

enum size_t stateSize;

static if(!(isPolymorphicType!T))

enum size_t stateSize;

}

Members

Variables

stateSize enum size_t stateSize;: Undocumented in source.
stateSize enum size_t stateSize;: Undocumented in source.

Parameters

T: Object type.

Return Value

Size of an instance of type T.

Examples

static assert(stateSize!int == 4);
static assert(stateSize!bool == 1);
static assert(stateSize!(int[]) == (size_t.sizeof * 2));
static assert(stateSize!(short[3]) == 6);

static struct Empty
{
}
static assert(stateSize!Empty == 1);
static assert(stateSize!void == 1);