Re: How to specify an exact template?
Well, it's quite complicated to do. I have to manually unwrap each and all function template, then pray for the compile-time optimization gods that they'll be inlined. This is so annoying, that I might issue a DIP...
Re: How define accepted types in a template parameter?
On Saturday, 16 January 2021 at 18:39:03 UTC, Marcone wrote:
For example, I want my function template to only accept integer
or string;
You can do that with either
- `static if` inside the body [1]
import std.traits;
void foo(T)(T t)
{
static if (isIntegral!T) {}
else static assert false;
}
- template constraint [2]
import std.traits;
void foo(T)(T t)
if (isIntegral!T)
{
}
- template parameter specialization [3]
void foo(T : ulong)(T t) // : meaning implictly convert to
{
}
2 and 3 being the more commonly used.
1 is more to use the same body instead of using N overloads
[1] : https://dlang.org/spec/version.html#staticif
[2] : https://dlang.org/spec/template.html#template_constraints
[3] :
https://dlang.org/spec/template.html#parameters_specialization
Re: How define accepted types in a template parameter?
On Saturday, 16 January 2021 at 18:39:03 UTC, Marcone wrote:
For example, I want my function template to only accept integer
or string;
There are different ways of doing that. I'd say this one is easy
to follow:
import std.stdio;
void print(T)(T entry) if(is(T==string) || is(T==int))
{
writeln(entry);
}
void main(){
int i = 5;
string foo = "foo";
double j = 0.6;
print(i);
print(foo);
print(j); // compilation error
}
How define accepted types in a template parameter?
For example, I want my function template to only accept integer or string;
Re: How to specify an exact template?
On Saturday, 16 January 2021 at 15:41:38 UTC, solidstate1991
wrote:
On Saturday, 16 January 2021 at 14:18:55 UTC, Tove wrote:
probably you can use
https://dlang.org/spec/traits.html#getOverloads
I don't know how to use it with functions outside of
structs/classes.
void foo() {}
void foo(string i) {}
static foreach(overload; __traits(getOverloads,
mixin(__MODULE__), "foo"))
pragma(msg, typeof(overload));
Re: How to specify an exact template?
On Saturday, 16 January 2021 at 14:18:55 UTC, Tove wrote: probably you can use https://dlang.org/spec/traits.html#getOverloads I don't know how to use it with functions outside of structs/classes.
Re: reference counting resources but NOT memory
What you are describing sounds like regular reference counting. All resources (i.e. windows) are pinned somewhere in memory. Its just that you have to use special API's to destroy them rather than free.
Re: How to specify an exact template?
On Saturday, 16 January 2021 at 14:14:57 UTC, solidstate1991 wrote: On Saturday, 16 January 2021 at 14:13:29 UTC, solidstate1991 wrote: Here's the following line, among many others: return !(ubyte); This generates an error, as this function template matches two instances, but currently I don't know how to choose the one I need, other than write a local function, that looks a bit ugly. Forgot to link the code example: https://github.com/ZILtoid1991/pixelperfectengine/blob/master/pixeperfectengine/src/PixelPerfectEngine/graphics/layers/base.d#L143 probably you can use https://dlang.org/spec/traits.html#getOverloads
Re: How to specify an exact template?
On Saturday, 16 January 2021 at 14:13:29 UTC, solidstate1991 wrote: Here's the following line, among many others: return !(ubyte); This generates an error, as this function template matches two instances, but currently I don't know how to choose the one I need, other than write a local function, that looks a bit ugly. Forgot to link the code example: https://github.com/ZILtoid1991/pixelperfectengine/blob/master/pixeperfectengine/src/PixelPerfectEngine/graphics/layers/base.d#L143
How to specify an exact template?
Here's the following line, among many others: return !(ubyte); This generates an error, as this function template matches two instances, but currently I don't know how to choose the one I need, other than write a local function, that looks a bit ugly.
reference counting resources but NOT memory
Is there any elegant/smart solution to reference counting resources without ever freeing any objects? When the ref hits 0 it should free some other resource that isn't memory... Resource[10] resources; resources[3].inc; // 1 ref - 0->1 transition enable some feature resources[3].dec; // 0 ref - 1->0 transition disable some feature resources[3].inc; // 1 ref - instantly ready to be used again without any alloc/free Maybe it's best to use normal constructor/destructor with some arena memory allocator that never actually frees anything? Must be a common problem, anyone got experience with a good design?
