digitalmars.D.learn - Handy templates
- Simen kjaeraas (84/84) May 26 2010 Here's a collection of templates I have created and use often. Some of
- Philippe Sigaud (10/14) May 27 2010 Hey, cool idea ! Do you have a site to put them online?
-
Simen kjaeraas
(54/54)
Jun 07 2010
Simen kjaeraas
Here's a collection of templates I have created and use often. Some of
these may be fit for inclusion in Phobos, others maybe not as much.
Please critique, and post your own indispensable snippets.
/**
Checks if one tuple contains another.
Example:
----
static assert(Contained!(int).In!(float, int));
static assert(!Contained!(int).In!(float, "foo"));
static assert(Contained!(int,"foo").In!(float, int, "foo", "bar"));
----
*/
template Contained(T...) {
template In(U...) {
static if (T.length == 0) {
enum In = true;
} else static if (U.length >= T.length) {
enum In = SameTuple!(T).As!( U[0..T.length]) ||
Contained!(T).In!(U[1..$]);
} else {
enum In = false;
}
}
}
unittest {
static assert(Contained!(int).In!(float, int));
static assert(!Contained!(int).In!(float, "foo"));
static assert(Contained!(int,"foo").In!(float, int, "foo", "bar"));
static assert(!Contained!(int,"foo").In!(float, int, "bar", "foo"));
static assert(Contained!().In!(float, int, "bar", "foo"));
}
/**
Evaluates to $(D F!(T[0..tupleLength]) &&
F!(T[tupleLength..2*tupleLength]) && ... && F[T[$-tupleLength..$]]).
Example:
----
static assert(allTuplesSatisfy!(Contained!(int).In, 2, int, float,
"foo", int));
static assert(!allTuplesSatisfy!(Contained!(int).In, 2, int, float,
"foo",string));
----
*/
template allTuplesSatisfy( alias F, uint tupleLength, T... ) {
static assert( !( T.length % tupleLength ) );
static if ( T.length == tupleLength ) {
enum allTuplesSatisfy = F!( T );
} else {
enum allTuplesSatisfy = F!( T[0..tupleLength] ) &&
allTuplesSatisfy!( F, tupleLength, T[tupleLength..$] );
}
}
unittest {
static assert(allTuplesSatisfy!(Contained!(int).In, 2, int, float,
"foo", int));
static assert(!allTuplesSatisfy!(Contained!(int).In, 2, int, float,
"foo",string));
}
/**
Repeats a type or tuple $(D num) times.
Example:
----
static assert(allTuplesSatisfy!(Contained!(int).In, 2, int, float,
"foo", int));
static assert(!allTuplesSatisfy!(Contained!(int).In, 2, int, float,
"foo",string));
----
*/
template Repeat( uint num, T... ) {
static if ( num > 1 ) {
alias TypeTuple!( T, Repeat!( num -1, T ) ) Repeat;
} else {
alias T Repeat;
}
}
unittest {
static assert(SameTuple!(Repeat!(4, int)).As!(int, int, int, int));
static assert(SameTuple!(Repeat!(4, "foo")).As!("foo", "foo", "foo",
"foo"));
static assert(SameTuple!(Repeat!(2, int, "foo")).As!(int, "foo", int,
"foo"));
static assert(!SameTuple!(Repeat!(2, int)).As!());
}
--
Simen
May 26 2010
On Thu, May 27, 2010 at 01:00, Simen kjaeraas <simen.kjaras gmail.com>wrote: Here's a collection of templates I have created and use often. Some of these may be fit for inclusion in Phobos, others maybe not as much. Please critique, and post your own indispensable snippets.Hey, cool idea ! Do you have a site to put them online? The one you call Repeat, I call TypeNuple and use it almost on a daily basis. I have a bunch of those there: http://svn.dsource.org/projects/dranges/trunk/dranges/docs/templates.html I'm particularly fond of Compose, TemplateParametersTypeTuple, and TemplateFunArity. Any comme I also have templates acting specifically on typetuples there: http://svn.dsource.org/projects/dranges/trunk/dranges/docs/typetuple2.html Strangely enough, I _have_ uses for things like StaticScan...
May 27 2010
Philippe Sigaud wrote:>On Thu, May 27, 2010 at 01:00, Simen kjaeraas <simen.kjaras gmail.com <mailto:simen.kjaras gmail.com>> wrote: >Here's a collection of templates I have created and use often. >Some of these may be fit for inclusion in Phobos, others maybe not as much. >Please critique, and post your own indispensable snippets. Hey, cool idea ! Do you have a site to put them online?If not, please put them in dsource/scrapple.The one you call Repeat, I call TypeNuple and use it almost on a daily basis. I have a bunch of those there: http://svn.dsource.org/projects/dranges/trunk/dranges/docs/templates.html I'm particularly fond of Compose, TemplateParametersTypeTuple, and TemplateFunArity. Any comme I also have templates acting specifically on typetuples there: http://svn.dsource.org/projects/dranges/trunk/dranges/docs/typetuple2.html Strangely enough, I _have_ uses for things like StaticScan...
May 28 2010
BCS <none anon.com> Hello Don,Philippe Sigaud wrote:If you need access, ping me and I'll get you in.If not, please put them in dsource/scrapple.On Thu, May 27, 2010 at 01:00, Simen kjaeraas <simen.kjaras gmail.com<mailto:simen.kjaras gmail.com>> wrote:Here's a collection of templates I have created and use often. Some of these may be fit for inclusion in Phobos, others maybe not asmuch.Please critique, and post your own indispensable snippets.Hey, cool idea ! Do you have a site to put them online?-- ... <IXOYE><The one you call Repeat, I call TypeNuple and use it almost on a daily basis. I have a bunch of those there: http://svn.dsource.org/projects/dranges/trunk/dranges/docs/templates. html I'm particularly fond of Compose, TemplateParametersTypeTuple, and TemplateFunArity. Any comme I also have templates acting specifically on typetuples there: http://svn.dsource.org/projects/dranges/trunk/dranges/docs/typetuple2 .html Strangely enough, I _have_ uses for things like StaticScan...
May 28 2010
Simen kjaeraas <simen.kjaras gmail.com> wrote:
Another few that showed up now with my work on combinatorial products of
ranges:
/**
Determines whether a template parameter is a type of value (alias).
Example:
----
template foo( T... ) if (allSatisfy!( isAlias, T ) {...}
----
*/
template isAlias( alias T ) {
enum isAlias = true;
}
template isAlias( T ) {
enum isAlias = false;
}
/**
Switches between template instantiations depending on the parameters
passed.
Example:
----
alias staticSwitch( foo, 1, 2, 3 ).With callFoo;
callFoo( 2 ); // Actually calls foo!(2)( )
----
*/
template staticSwitch( alias F, T... ) if ( allSatisfy!( isAlias, T ) ) {
auto With( CommonType!T index, ParameterTypeTuple!( F!( T[0] ) ) args
) {
switch ( index ) {
foreach ( i, e; T ) {
mixin( Format!( q{case %s:}, e ) );
return F!( e )( args );
break;
}
}
assert( false );
}
}
version( unittest ) {
int foo( int n ) {
return n;
}
}
unittest {
assert( staticSwitch!( foo, 1, 2 ).With( 2 ) == 2 );
}
The latter does currently not work, due to bug 4292, but a patch has been
submitted. Granted, a simple template would work around that problem, but
better to remove it at the root.
Philippe, if you or anyone else want to add any of these templates to your
dranges or their own collection of templates, I would be pleased to allow
it. But please do give credit.
--
Simen
Jun 07 2010