1 static struct Foo
2 {
3 pure nothrow @nogc:
4 this(int* ptr) { _ptr = ptr; }
5 ~this() { if (_ptr) ++*_ptr; }
6 int* _ptr;
7 }
8
9 int val;
10 Foo foo1 = void; // uninitialized
11 auto foo2 = Foo(&val); // initialized
12 assert(foo2._ptr is &val);
13
14 // Using `move(foo2, foo1)` would have an undefined effect because it would destroy
15 // the uninitialized foo1.
16 // moveEmplace directly overwrites foo1 without destroying or initializing it first.
17 moveEmplace(foo2, foo1);
18 assert(foo1._ptr is &val);
19 assert(foo2._ptr is null);
20 assert(val == 0);
The D Programming Language's Unofficial Docs
beta
Similar to move but assumes target is uninitialized. This is more efficient because source can be blitted over target without destroying or initializing it first.