Re: Check if tuple contains value at compile time
Diggory: Is the behaviour of the empty [] when applied to tuples documented anywhere? I don't remember. The problem is that this doesn't work if the tuple is empty: Error: template std.algorithm.canFind does not match any function template declaration. And unfortunately in the situation I need it for an empty tuple is one of the most likely scenarios. I see. Then a good idea is to create a little function, to solve this. It should contain a static if that tests for the empty tuple and returns false in that case, and otherwise uses the canFind. Bye, bearophile
Re: Check if tuple contains value at compile time
On Sunday, 5 May 2013 at 01:44:19 UTC, bearophile wrote:
Diggory:
The documentation seems too say that "[mytuple]" will make an
array,
Nope. You have to extract the inherent typetuple first. And
this is what the [] syntax does (tested):
import std.stdio, std.typecons, std.algorithm;
void main() {
auto t = tuple("foo", "bar", "spam");
assert([t[]].canFind("bar"));
}
Bye,
bearophile
Is the behaviour of the empty [] when applied to tuples
documented anywhere?
The problem is that this doesn't work if the tuple is empty:
Error: template std.algorithm.canFind does not match any function
template declaration.
And unfortunately in the situation I need it for an empty tuple
is one of the most likely scenarios.
Re: Check if tuple contains value at compile time
Diggory:
The documentation seems too say that "[mytuple]" will make an
array,
Nope. You have to extract the inherent typetuple first. And this
is what the [] syntax does (tested):
import std.stdio, std.typecons, std.algorithm;
void main() {
auto t = tuple("foo", "bar", "spam");
assert([t[]].canFind("bar"));
}
Bye,
bearophile
Re: Check if tuple contains value at compile time
On Sunday, 5 May 2013 at 00:33:34 UTC, bearophile wrote: Diggory: It's not a TypeTuple, it's a tuple of strings. Then one simple way to do it is to convert it into an array of strings, and then use canFind: [mytuple[]].canFind(needle) Bye, bearophile OK, that makes sense but I'm not sure I understand that syntax. The documentation seems too say that "[mytuple]" will make an array, or that "mytuple[]" will make a slice from a tuple (presumably with no arguments it will slice the entire tuple?), so how does "[mytuple[]]" work?
Re: Check if tuple contains value at compile time
Diggory: It's not a TypeTuple, it's a tuple of strings. Then one simple way to do it is to convert it into an array of strings, and then use canFind: [mytuple[]].canFind(needle) Bye, bearophile
Re: Check if tuple contains value at compile time
On Sunday, 5 May 2013 at 00:10:27 UTC, Simen Kjaeraas wrote: On 2013-05-05, 01:42, Diggory wrote: I'm trying to test using a "static if" statement if a tuple of strings contains a particular string. What's the easiest/best way to do this? http://dlang.org/phobos/std_typetuple#.staticIndexOf It's not a TypeTuple, it's a tuple of strings.
Re: Check if tuple contains value at compile time
On 2013-05-05, 01:42, Diggory wrote: I'm trying to test using a "static if" statement if a tuple of strings contains a particular string. What's the easiest/best way to do this? http://dlang.org/phobos/std_typetuple#.staticIndexOf -- Simen
Check if tuple contains value at compile time
I'm trying to test using a "static if" statement if a tuple of strings contains a particular string. What's the easiest/best way to do this?
