Tuple with more than two fields

Fix #41.
This commit is contained in:
Eugen Wissner 2018-06-19 05:44:15 +02:00
parent a86b6690f0
commit de15281ccb

View File

@ -17,6 +17,7 @@
*/
module tanya.typecons;
import tanya.format;
import tanya.meta.metafunction : AliasSeq, AliasTuple = Tuple, Map;
deprecated("Use tanya.typecons.Tuple instead")
@ -77,11 +78,10 @@ template Pair(Specs...)
}
/**
* $(D_PSYMBOL Tuple) can store two heterogeneous objects.
* $(D_PSYMBOL Tuple) can store two or more heterogeneous objects.
*
* The objects can by accessed by index as $(D_INLINECODE obj[0]) and
* $(D_INLINECODE obj[1]) or by optional names (e.g.
* $(D_INLINECODE obj.first)).
* The objects can by accessed by index as `obj[0]` and `obj[1]` or by optional
* names (e.g. `obj.first`).
*
* $(D_PARAM Specs) contains a list of object types and names. First
* comes the object type, then an optional string containing the name.
@ -123,7 +123,26 @@ template Tuple(Specs...)
alias ChooseType(alias T) = T.Seq[0];
alias ParsedSpecs = parseSpecs!(0, Specs);
static assert(ParsedSpecs.length == 2, "Invalid argument count");
static assert(ParsedSpecs.length > 1, "Invalid argument count");
private string formatAliases(size_t n, Specs...)()
{
static if (Specs.length == 0)
{
return "";
}
else
{
string fieldAlias;
static if (Specs[0].length == 2)
{
char[21] buffer;
fieldAlias = "alias " ~ Specs[0][1] ~ " = expand["
~ integral2String(n, buffer).idup ~ "];";
}
return fieldAlias ~ formatAliases!(n + 1, Specs[1 .. $])();
}
}
struct Tuple
{
@ -131,14 +150,7 @@ template Tuple(Specs...)
alias Types = Map!(ChooseType, ParsedSpecs);
// Create field aliases.
static if (ParsedSpecs[0].length == 2)
{
mixin("alias " ~ ParsedSpecs[0][1] ~ " = expand[0];");
}
static if (ParsedSpecs[1].length == 2)
{
mixin("alias " ~ ParsedSpecs[1][1] ~ " = expand[1];");
}
mixin(formatAliases!(0, ParsedSpecs[0 .. $])());
/// Represents the values of the $(D_PSYMBOL Tuple) as a list of values.
Types expand;
@ -171,4 +183,7 @@ template Tuple(Specs...)
static assert(!is(Tuple!(int, int, int)));
static assert(!is(Tuple!(int, "first")));
static assert(!is(Tuple!(int, double, char)));
static assert(!is(Tuple!(int, "first", double, "second", char, "third")));
}