https://gcc.gnu.org/bugzilla/show_bug.cgi?id=59832
Matthijs van Duin <matthijsvanduin at gmail dot com> changed:
What |Removed |Added
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CC| |matthijsvanduin at gmail dot
com
--- Comment #13 from Matthijs van Duin <matthijsvanduin at gmail dot com> ---
I also just ran into this one with g++ 6.2.1.
Here are some interesting cases:
union Foo {
union { int x; char y; } u;
union { int x; char y; } v;
int n;
};
std::vector<Foo> foo = {
{}, // ok
{ .u = {} }, // ok
{ .u = { .x = {} } }, // ok
{ .u = { .x = 0 } }, // ok
{ .u = { .y = {} } }, // ICE in reshape_init_class
{ .u = { .y = 0 } }, // ICE in reshape_init_class
{ .v = {} }, // ok
{ .v = { .x = {} } }, // ICE in reshape_init_class
{ .v = { .x = 0 } }, // ICE in reshape_init_class
{ .v = { .y = {} } }, // ICE in reshape_init_class
{ .v = { .y = 0 } }, // ICE in reshape_init_class
{ .n = {} }, // ok
{ .n = 0 }, // error: could not convert
};
Some more observations:
- Replacing the inner unions by structs results in the same errors (in addition
to some warnings for missing initializers)
- No errors occur if a C-style array is initialized instead of std::vector
- It doesn't matter if the inner aggregates are anonymous or not.
Similar things with an outer struct:
struct Bar {
union { int x; char y; } u;
union { int x; char y; } v;
};
std::vector<Bar> bar = {
{ .u = {}, .v = {} }, // ok
{ .u = {}, .v = { .x = 0 } }, // ok
// { .u = {}, .v = { .y = 0 } }, // ICE in reshape_init_class
{ .u = { .x = 0 }, .v = {} }, // ok
// { .u = { .y = 0 }, .v = {} }, // ICE in reshape_init_class
// { .v = { .x = 0 }, .u = {} }, // ICE in reshape_init_class
// { .v = {}, .u = { .x = 0 } }, // ICE in reshape_init_class
// { .v = {}, .u = {} }, // sorry, unimplemented
};
