On Saturday, 30 January 2016 at 00:16:21 UTC, Ali Çehreli wrote:
> https://issues.dlang.org/show_bug.cgi?id=15623
As I noted on the bug report, they are work when moved from
module scope to inside a function (e.g. main()). At least
there's that workaround...
Ali
Thanks a lot! Now I can con
On Friday, 29 January 2016 at 23:44:56 UTC, Basile B. wrote:
Haven't you seen my answer about constraint ?
If you put a constraint on your function template then invalid
instantiations are rejected. I mean... this language feature is
not just ornamental...
What do you think constraints are u
On 01/29/2016 09:01 AM, Adrian Matoga wrote:
> Oh, there's more:
> // this should fail:
> static assert(is(CallsFoo!NoFoo));
> // this should fail too:
> static assert(is(typeof({ alias Baz = CallsFoo!NoFoo; return Baz.init;
> }(;
> // and this:
> static assert(__traits(compiles, { alias Baz
On 1/29/16 6:44 PM, Basile B. wrote:
Haven't you seen my answer about constraint ?
If you put a constraint on your function template then invalid
instantiations are rejected. I mean... this language feature is not just
ornamental...
What do you think constraints are used for otherwise ^^
A c
On Friday, 29 January 2016 at 17:01:46 UTC, Adrian Matoga wrote:
On Friday, 29 January 2016 at 16:36:01 UTC, Steven
Schveighoffer wrote:
On 1/29/16 10:28 AM, Adrian Matoga wrote:
[...]
is(T) is supposed to be false if T is not a valid type.
I would agree with you that the static assert shoul
On Friday, 29 January 2016 at 16:36:01 UTC, Steven Schveighoffer
wrote:
On 1/29/16 10:28 AM, Adrian Matoga wrote:
Code:
struct HasFoo { void foo() {} }
struct NoFoo {}
struct CallsFoo(T) {
T t;
void bar() { t.foo(); }
}
static assert(is(CallsFoo!HasFoo));
alias Bar = CallsFoo!
On 1/29/16 10:28 AM, Adrian Matoga wrote:
Code:
struct HasFoo { void foo() {} }
struct NoFoo {}
struct CallsFoo(T) {
T t;
void bar() { t.foo(); }
}
static assert(is(CallsFoo!HasFoo));
alias Bar = CallsFoo!HasFoo;
static assert(is(CallsFoo!NoFoo)); // (1)
//alias Baz = CallsFoo
On Friday, 29 January 2016 at 15:28:29 UTC, Adrian Matoga wrote:
How can I reliably test if CallsFoo can be instantiated?
You can use a constraint to prevent invalid instantiation:
struct HasFoo { void foo() {} }
struct NoFoo {}
struct CallsFoo(T)
if (__traits(hasMember, T, "foo"))
{
Code:
struct HasFoo { void foo() {} }
struct NoFoo {}
struct CallsFoo(T) {
T t;
void bar() { t.foo(); }
}
static assert(is(CallsFoo!HasFoo));
alias Bar = CallsFoo!HasFoo;
static assert(is(CallsFoo!NoFoo)); // (1)
//alias Baz = CallsFoo!NoFoo; // (2)
This compil
