https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85889
Bug ID: 85889
Summary: lambda expression can capture structured bindings
Product: gcc
Version: 8.1.1
Status: UNCONFIRMED
Keywords: accepts-invalid
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: redi at gcc dot gnu.org
Target Milestone: ---
[expr.prim.lambda.capture] p8 says "If a lambda-expression explicitly captures
an entity that is not odr-usable or captures a structured binding (explicitly
or implicitly), the program is ill-formed."
With -std=c++17 this compiles without any diagnostic:
struct X { int i, j; };
void f() {
X x{};
auto [i, j] = x;
[&i]() { };
}
Clang says:
l.cc:5:5: error: 'i' in capture list does not name a variable
[&i]() { };
^
l.cc:5:3: warning: expression result unused [-Wunused-value]
[&i]() { };
^~~~~~~~~~
1 warning and 1 error generated.
And EDG says:
"l.cc", line 5: error: structured binding cannot be captured
[&i]() { };
^
"l.cc", line 4: warning: variable "i" was declared but never referenced
auto [i, j] = x;
^
"l.cc", line 4: warning: variable "j" was declared but never referenced
auto [i, j] = x;
^
1 error detected in the compilation of "l.cc".
