and a function template instantiation, if there's a parameter pack in the
declaration and one at the same place in the instantiation, don't assume that
the pack wasn't expanded -- it may have expanded to nothing. Instead, go ahead
and check whether the parameter pack was expandable. We can do this as a
side-effect of the work we'd need to do anyway, to find how many parameters
were produced.
llvm-svn: 160416
of an expansion, and we have a paramameter that is not a parameter
pack, don't suppress substitution of parameter packs within this
context.
llvm-svn: 126819
a pack expansion, e.g., the parameter pack Values in:
template<typename ...Types>
struct Outer {
template<Types ...Values>
struct Inner;
};
This new implementation approach introduces the notion of an
"expanded" non-type template parameter pack, for which we have already
expanded the types of the parameter pack (to, say, "int*, float*",
for Outer<int*, float*>) but have not yet expanded the values. Aside
from creating these expanded non-type template parameter packs, this
patch updates template argument checking and non-type template
parameter pack instantiation to make use of the appropriate types in
the parameter pack.
llvm-svn: 123845
template template parameter pack that cannot be fully expanded because
its enclosing pack expansion could not be expanded. This form of
TemplateName plays the same role as SubstTemplateTypeParmPackType and
SubstNonTypeTemplateParmPackExpr do for template type parameter packs
and non-type template parameter packs, respectively.
We should now handle these multi-level pack expansion substitutions
anywhere. The largest remaining gap in our variadic-templates support
is that we cannot cope with non-type template parameter packs whose
type is a pack expansion.
llvm-svn: 123521
that captures the substitution of a non-type template argument pack
for a non-type template parameter pack within a pack expansion that
cannot be fully expanded. This follows the approach taken by
SubstTemplateTypeParmPackType.
llvm-svn: 123506
expansion, when it is known due to the substitution of an out
parameter pack. This allows us to properly handle substitution into
pack expansions that involve multiple parameter packs at different
template parameter levels, even when this substitution happens one
level at a time (as with partial specializations of member class
templates and the signatures of member function templates).
Note that the diagnostic we provide when there is an arity mismatch
between an outer parameter pack and an inner parameter pack in this
case isn't as clear as the normal diagnostic for an arity
mismatch. However, this doesn't matter because these cases are very,
very rare and (even then) only typically occur in a SFINAE context.
The other kinds of pack expansions (expression, template, etc.) still
need to support optional tracking of the number of expansions, and we
need the moral equivalent of SubstTemplateTypeParmPackType for
substituted argument packs of template template and non-type template
parameters.
llvm-svn: 123448
involve template parameter packs at multiple template levels that
occur within the signatures members of class templates (and partial
specializations thereof). This is a work-in-progress that is deficient
in several ways, notably:
- It only works for template type parameter packs, but we need to
also support non-type template parameter packs and template template
parameter packs.
- It doesn't keep track of the lengths of the substituted argument
packs in the expansion, so it can't properly diagnose length
mismatches.
However, this is a concrete step in the right direction.
llvm-svn: 123425
Richard Smith