default template argument expression.
We already did this for type template parameters and template template
parameters, but apparently forgot to do so for non-type template
parameters. This causes the substituted default argument expression to
be substituted in the proper context, and in particular to properly mark
its subexpressions as odr-used.
llvm-svn: 369834
Summary:
[[ https://bugs.llvm.org/show_bug.cgi?id=41549 | bug report ]]
Before this patch, implicit deduction guides were generated from the first declaration found by lookup.
With this patch implicit deduction guides are generated from the definition of the class template.
Also added test that was previously failing.
Reviewers: rsmith
Reviewed By: rsmith
Subscribers: cfe-commits, Quuxplusone
Tags: #clang
Differential Revision: https://reviews.llvm.org/D63072
llvm-svn: 363361
Summary:
Some style guides want to allow using CTAD only on types that "opt-in"; i.e. on types that are designed to support it and not just types that *happen* to work with it.
This patch implements the `-Wctad-maybe-unsupported` warning, which is off by default, which warns when CTAD is used on a type that does not define any deduction guides.
The following pattern can be used to suppress the warning in cases where the type intentionally doesn't define any deduction guides:
```
struct allow_ctad_t;
template <class T>
struct TestSuppression {
TestSuppression(T) {}
};
TestSuppression(allow_ctad_t)->TestSuppression<void>; // guides with incomplete parameter types are never considered.
```
Reviewers: rsmith, james.dennett, gromer
Reviewed By: rsmith
Subscribers: jdennett, Quuxplusone, lebedev.ri, cfe-commits
Differential Revision: https://reviews.llvm.org/D56731
llvm-svn: 351484
Previously, we just canonicalized the type, but this lead to crashes with
parameter types that referred to ParmVarDecls of the constructor. There may be
more cases that this TreeTransform needs to handle though, such as a constructor
parameter type referring to a member in an unevaluated context. Canonicalization
doesn't address these cases either though, so we can address them as-needed in
follow-up commits.
rdar://41330135
Differential revision: https://reviews.llvm.org/D49439
llvm-svn: 338165
during template argument deduction.
We already did this when the injected-class-name was in P, but missed the case
where it was in A. This (probably) can't happen except in implicit deduction
guides.
llvm-svn: 321779
RecursiveASTVisitor was not properly recursing through a
SubstTemplateTypeParmTypes, resulting in crashes in pack expansion where we
couldn't always find an unexpanded pack within a pack expansion.
We also have an issue where substitution of deduced template arguments for an
implicit deduction guide creates the "impossible" case of naming a
non-dependent member of the current instantiation, but within a specialization
that is actually instantiated from a different (partial/explicit)
specialization of the template. We resolve this by declaring that constructors
that do so can only be used to deduce specializations of the primary template.
I'm running this past CWG to see if people agree this is the right thing to do.
llvm-svn: 304862
This reverts an attempt to check that types match when matching a
dependently-typed non-type template parameter. (This comes up when matching the
parameters of a template template parameter against the parameters of a
template template argument.)
The matching rules here are murky at best. Our behavior after this revert is
definitely wrong for certain C++17 features (for 'auto' template parameter
types within the parameter list of a template template argument in particular),
but our behavior before this revert is wrong for some pre-existing testcases,
so reverting to our prior behavior seems like our best option.
llvm-svn: 300262
We need to look through the PackExpansionType in the parameter type when
deducing, and we need to consider the possibility of deducing arguments for
packs that are not lexically mentioned in the pattern (but are nonetheless
deducible) when figuring out which packs are covered by a pack deduction scope.
llvm-svn: 295790
case where the class template has a parameter pack.
Checking of the template arguments expects an "as-written" template argument
list, which in particular does not have any parameter packs. So flatten the
packs into separate arguments before passing them in.
llvm-svn: 295710
template deduction guides for class template argument deduction.
Ensure that we have a local instantiation scope for tracking the instantiated
parameters. Additionally, unusually, we're substituting at depth 1 and leaving
depth 0 alone; make sure that we don't reduce template parameter depth by 2 for
inner parameters in the process. (This is probably also broken for alias
templates in the case where they're expanded within a dependent context, but
this patch doesn't fix that.)
llvm-svn: 295696
guide from a constructor.
The purpose of this change is to avoid triggering instantiation of the class
when substituting back into the deduction guide if it uses a typedef member.
We will still instantiate the class if the constructor (explicitly or
implicitly, directly or indirectly) uses the current instantiation in a way
that we can't canonicalize out, but that seems unavoidable.
llvm-svn: 295016
Richard Smith