From 7bf8f6fa8ab123fe97ccd82d9a0ddff85505ee5f Mon Sep 17 00:00:00 2001 From: Richard Smith Date: Tue, 4 Jun 2019 17:17:20 +0000 Subject: PR42104: Support instantiations of lambdas that implicitly capture packs. Two changes: * Track odr-use via FunctionParmPackExprs to properly handle dependent odr-uses of packs in generic lambdas. * Do not instantiate implicit captures; instead, regenerate them by instantiating the body of the lambda. This is necessary to distinguish between cases where only one element of a pack is captured and cases where the entire pack is captured. This reinstates r362358 (reverted in r362375) with a fix for an uninitialized variable use in UpdateMarkingForLValueToRValue. llvm-svn: 362531 --- clang/test/SemaTemplate/lambda-capture-pack.cpp | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) create mode 100644 clang/test/SemaTemplate/lambda-capture-pack.cpp (limited to 'clang/test/SemaTemplate/lambda-capture-pack.cpp') diff --git a/clang/test/SemaTemplate/lambda-capture-pack.cpp b/clang/test/SemaTemplate/lambda-capture-pack.cpp new file mode 100644 index 00000000000..2fe576769db --- /dev/null +++ b/clang/test/SemaTemplate/lambda-capture-pack.cpp @@ -0,0 +1,17 @@ +// RUN: %clang_cc1 -std=c++2a -verify %s +// expected-no-diagnostics + +template void check_sizes(Lambda ...L) { + static_assert(((sizeof(T) == sizeof(Lambda)) && ...)); +} + +template void f(T ...v) { + // Pack expansion of lambdas: each lambda captures only one pack element. + check_sizes([=] { (void)&v; } ...); + + // Pack expansion inside lambda: captures all pack elements. + auto l = [=] { ((void)&v, ...); }; + static_assert(sizeof(l) >= (sizeof(T) + ...)); +} + +template void f(int, char, double); -- cgit v1.2.3