corresponding arguments are unexpanded pack expansions, we can compute the
result without substituting them. This significantly improves the memory usage
and performance of make_integer_sequence implementations that do this kind of
thing:
using result = integer_sequence<T, Ns ..., sizeof...(Ns) + Ns ...>;
... but note that such an implementation will still perform O(sizeof...(Ns)^2)
work while building the second pack expansion (we just have a somewhat lower
constant now).
In principle we could get this down to linear time by caching whether the
number of expansions of a pack is constant, or checking whether we're within an
alias template before scanning the pack for pack expansions (since that's the
only case in which we do substitutions within a dependent context at the
moment), but this patch doesn't attempt that.
llvm-svn: 284653
they're redeclarations. This is necessary in order for name lookup to correctly
find the most recent declaration of the name (which affects default template
argument lookup and cross-module merging, among other things).
llvm-svn: 275612
This doesn't quite get alias template equivalence right yet, but handles the
egregious cases where we would silently give the wrong answers.
llvm-svn: 248431
When we are parsing a type for an alias template, we are not entering
the context, so we can't look into dependent classes. Make sure the
parser handles this correctly.
PR16904.
llvm-svn: 188510
This patch essentially removes all the FIXMEs following calls to DeduceTemplateArguments() that want to keep track of deduction failure info.
llvm-svn: 186730
When we see a pack, and replace it with a template argument which is
also a pack, we want to use the pack pattern, not the expanded pack.
The caller should take care of expanding the pack afterwards.
Fixes PR16646.
llvm-svn: 186713
being a property of a canonical type to being a property of the fully-sugared
type. This should only make a difference in the case where an alias template
ignores one of its parameters, and that parameter is an unexpanded parameter
pack.
llvm-svn: 160244
* When substituting a reference to a non-type template parameter pack where the
corresponding argument is a pack expansion, transform into an expression
which contains an unexpanded parameter pack rather than into an expression
which contains a pack expansion. This causes the SubstNonTypeTemplateParmExpr
to be inside the PackExpansionExpr, rather than outside, so the expression
still looks like a pack expansion and can be deduced.
* Teach MarkUsedTemplateParameters that we can deduce a reference to a template
parameter if it's wrapped in a SubstNonTypeTemplateParmExpr (such nodes are
added during alias template substitution).
llvm-svn: 159922
expression, skip over any SubstNonTypeTemplateParmExprs which alias templates
may have inserted before checking for a DeclRefExpr referring to a non-type
template parameter declaration.
llvm-svn: 159909
iff its substitution contains an unexpanded parameter pack. This has the effect
that we now reject declarations such as this (which we used to crash when
expanding):
template<typename T> using Int = int;
template<typename ...Ts> void f(Int<Ts> ...ints);
The standard is inconsistent on how this case should be treated.
llvm-svn: 148905
Richard Smith