On Tue, 30 Nov 2010 16:05:16 -0500, Walter Bright
<newshou...@digitalmars.com> wrote:
Steven Schveighoffer wrote:
On Tue, 30 Nov 2010 15:16:04 -0500, Walter Bright
<newshou...@digitalmars.com> wrote:
Steven Schveighoffer wrote:
The example that I gave does not seem to you like it would surprise
someone? I passed in a const object and it got modified, even though
no casts were used.
No, it doesn't surprise me. Const on one object does not apply to
another object.
So this:
void myfn(const(C) n)
{
assert(n.x == 1);
n.foo();
assert(n.x == 5);
}
Wouldn't be surprising to you?
No. There are a lot of things a member "x" could be. The const only
applies to the instance data.
If you read my previous code, x is instance data. I'll reiterate the
class definition:
class C
{
static C theCommonOne;
int x;
void foo() const {
theCommonOne.x = 5; // theCommonOne could be this
}
}
If you find the above unsurprising, you are in the minority. I find it
surprising, and invalid that anyone would write code this way. People
simply just don't do that normally. It's just written to demonstrate a
point that the compiler does not guarantee anything via const, it's
guaranteed by convention. The compiler simply helps you follow the
convention.
-Steve
