On Tuesday, 17 April 2012 at 12:46:28 UTC, Kenji Hara wrote:
On Tuesday, 17 April 2012 at 12:04:44 UTC, Erèbe wrote:
[snip]
There is something I still don't understand :
mixin template Foo( T... )
{
//Code here
}
mixin Foo!( "Hello", "Word" ); <---- Good
T is TemplateTypeParameter, and matches any kind of template
arguments - types, values, and symbols. The both arguments
"Hello" and "World" are values, so you can bind them with T.
http://dlang.org/template.html#TemplateTupleParameter
--------------------------------------------
"mixin template Foo( A, T... )
{
//code here
}
mixin Foo!( "Hello", "Word" ); <--- Fail !
mixin Foo!( string, "Word" ); <---- Good
--------------------------------------------
'A' is TemplateTypeParameter, and it matches only types. In the
first instantiation of Foo, A doesn't match with the value
"hello".
In the second instantiation, string is type, and T matches with
it.
http://dlang.org/template.html#TemplateTypeParameter
mixin template Foo( alias A, T... )
{
//code here
}
mixin Foo!( "Hello", "world" ); <--- Good
mixin Foo!( string, "world" ); <--- Fail !
---------------------------------------------
'alias A' is TemplateAliasParameter, and it matches both
symbols and values.
Then A matches with the value "Hello", but doesn't with the
type string.
(string is an aliased name of immutable(char)[], and it is
built-in array type.)
http://dlang.org/template.html#TemplateAliasParameter
Kenji Hara
Thanks a lot Kenji Hara,
I have a better understanding of it now !
