[libcxx-commits] [libcxx] [libc++][string] Remove potential non-trailing 0-length array (PR #105865)

[Louis Dionne via libcxx-commits]

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@@ -748,6 +748,41 @@ struct __can_be_converted_to_string_view
 struct __uninitialized_size_tag {};
 struct __init_with_sentinel_tag {};
 
+#ifdef _LIBCPP_ABI_ALTERNATE_STRING_LAYOUT
+template <class _CharT, size_t __min_cap, size_t _Padding = sizeof(_CharT) - 1>
+struct __short_impl {
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ldionne wrote:

I would like to do this:

```c++
// always define both of these classes
template <class _CharT, size_t __min_cap, size_t _Padding = sizeof(_CharT) - 1>
struct __short_layout_alternate { ... };

template <class _CharT, size_t __min_cap, size_t _Padding = sizeof(_CharT) - 1>
struct __short_layout_classic { ... };

// now inside basic_string
#ifdef _LIBCPP_ABI_ALTERNATE_STRING_LAYOUT
using __short = __short_layout_alternate <value_type, __min_cap>;
#else
using __short = __short_layout_classic <value_type, __min_cap>;
#endif
```

This reduces the scope of the conditional code and IMO makes things easier to understand.

https://github.com/llvm/llvm-project/pull/105865