emplace

Constructs a new object of type T in memory with the given arguments.

If T is a $(D_KEYWORD class), emplace returns a class reference of type T, otherwise a pointer to the constructed object is returned.

If T is a nested class inside another class, outer should be an instance of the outer class.

args are arguments for the constructor of T. If T isn't an aggregate type and doesn't have a constructor, memory can be initialized to args[0] if Args.length == 1, Args[0] should be implicitly convertible to T then.

T emplace(void[] memory, U outer, Args args)
T emplace(void[] memory, Args args)
T* emplace(void[] memory, Args args)
T*
emplace
(
T
Args...
)
(
void[] memory
,
auto ref Args args
)
if (
!isAggregateType!T &&
(Args.length <= 1)
)
out (result) { assert (memory.ptr is result); }
T* emplace(void[] memory, Args args)

Parameters

T: Constructed type.
Args: Types of the constructor arguments if T has a constructor or the type of the initial value.
args Args: Constructor arguments if T has a constructor or the initial value.

Return Value

Type: T*

New instance of type T constructed in memory.

Precondition: memory.length == stateSize!T. Postcondition: memory and the result point to the same memory.

Examples

class C
{
    int i = 5;
    class Inner
    {
        int i;

        this(int param) pure nothrow @safe @nogc
        {
            this.i = param;
        }
    }
}
ubyte[stateSize!C] memory1;
ubyte[stateSize!(C.Inner)] memory2;

auto c = emplace!C(memory1);
assert(c.i == 5);

auto inner = emplace!(C.Inner)(memory2, c, 8);
assert(c.i == 5);
assert(inner.i == 8);
assert(inner.outer is c);

emplace

Parameters

Return Value

Examples

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