8 Commits

Author SHA1 Message Date
Younan Zhang
3eeed79946
[clang] Correctly implement CWG 2672 (#75001) 2024-01-05 20:36:41 +08:00
Ilya Biryukov
629170fe45 [Sema] Lambdas are not part of immediate context for deduction
This commit implements [temp.deduct]p9.
Test updates include:
- New notes in `cxx1y-init-captures.cpp`, `lambda-expressions.cpp`
  and 'warn-unused-lambda-capture.cpp'.
  This seems to be caused by diagnosing errors earlier (during
  deduction) that were previously surfaced later (during
  instantiation).
- New error `lambda-unevaluated.cpp` is in line with [temp.deduct]p9.

Reviewed By: erichkeane, #clang-language-wg

Differential Revision: https://reviews.llvm.org/D148802
2023-05-09 12:06:33 +02:00
Richard Smith
b2997f579a [c++20] P0780R2: Support pack-expansion of init-captures.
This permits an init-capture to introduce a new pack:

  template<typename ...T> auto x = [...a = T()] { /* a is a pack */ };

To support this, the mechanism for allowing ParmVarDecls to be packs has
been extended to support arbitrary local VarDecls.

llvm-svn: 361300
2019-05-21 20:10:50 +00:00
Richard Smith
5b013f5050 Add compat/extension warnings for init captures.
llvm-svn: 191609
2013-09-28 05:38:27 +00:00
Richard Smith
bb13c9a49d Per latest drafting, switch to implementing init-captures as if by declaring
and capturing a variable declaration, and complete the implementation of them.

llvm-svn: 191605
2013-09-28 04:02:39 +00:00
Richard Smith
ba71c08523 First pass of semantic analysis for init-captures: check the initializer, build
a FieldDecl from it, and propagate both into the closure type and the
LambdaExpr.

You can't do much useful with them yet -- you can't use them within the body
of the lambda, because we don't have a representation for "the this of the
lambda, not the this of the enclosing context". We also don't have support or a
representation for a nested capture of an init-capture yet, which was intended
to work despite not being allowed by the current standard wording.

llvm-svn: 181985
2013-05-16 06:20:58 +00:00
Richard Smith
2589b9808e PR12057: Allow variadic template pack expansions to cross lambda boundaries.
Rather than adding a ContainsUnexpandedParameterPack bit to essentially every
AST node, we tunnel the bit directly up to the surrounding lambda expression
when we reach a context where an unexpanded pack can not normally appear.
Thus any statement or declaration within a lambda can now potentially contain
an unexpanded parameter pack.

llvm-svn: 160705
2012-07-25 03:56:55 +00:00
Douglas Gregor
3e308b1fba Implement support for lambda capture pack expansions, e.g.,
[&values...] { print(values...); }

llvm-svn: 150497
2012-02-14 19:27:52 +00:00