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[QUESTION] Mutable that in move constructor? #715
Description
How on earth do I write a move constructor that resets the moved from object? (Like setting pointers to null or the like).
Going from this:
struct Bar {
int b = 5;
Bar(int b_): b(b_) {}
Bar(Bar& that) {
this->b = that.b;
that.b = 0;
}
};I tried to write this:
Foo: @struct type = {
public a: i32 = 5;
operator=: (out this, a_: i32) = {
a = a_;
}
operator=: (out this, inout that) = {
this.a = that.a + 1;
that.a = 0;
}
}But I'm only allowed to use in or move for that? Surely this is not just unsupported?
Sorry to take up space in the issue tracker, but I'm not aware of any better forum.
Activity
[-][QUESTION] [/-][+][QUESTION] Mutable `that` in move constructor?[/+]jituderaps commentedon Oct 1, 2023
In cpp1, move constructor (
T (T&& that)) only invoked when you construct an object of type T with an T's rvalue.i.e.
in above case, move constructor(
Point(Point&& that)) get invoked to construct variable p2.so,
Bar (Bar& that)is not a syntax of move constructor.In cpp2, the syntax for move constructor is :
operator=:(out this, move that) = {};.And if you still want to do same thing as
Bar (Bar& arg)in cpp2, then you can do that as given below:operator=: (out this, inout rhs: Bar) = {}.JohelEGP commentedon Oct 1, 2023
https://github.com/hsutter/cppfront/discussions/categories/q-a is a place for questions.
SebastianTroy commentedon Oct 2, 2023