Fix GCC 10-15 warnings (-Wall -Wextra), including several real bugs, upstream #421 and part of #260 - #6

…asserts

variadicAnd(bool cond, bool conds...) was a C varargs function, so it only
checked its first two arguments: tuple_vector's iterator validation
ignored every element type after the second. It's now a variadic template.

The index-out-of-range static_asserts in tuple and tuple_vector used
I != I, which GCC 14 reports with -Wtautological-compare. They use an
always-false trait that depends on I instead.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

… types (upstream electronicarts#421)

The forwarding overloads reinterpret_cast the callers' pointer variables
(for example const char8_t*& to const char*&) and write through them,
which breaks strict aliasing; GCC reports it with -Wstrict-aliasing. They
now go through details::DecodePartAs, which converts the pointer values
and writes them back.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

…alized members

begin() const and end() const filled an iterator and returned it as a
const_iterator&, a different type, and end() left mEnd and mSegment
uninitialized (GCC: -Wstrict-aliasing, -Wuninitialized). They now build a
value-initialized const_iterator, and the non-const versions value-
initialize their iterator too.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

operator"" sv with a space is deprecated since C++23 (CWG 2521); GCC 15
reports it with -Wdeprecated-literal-operator. The suffixes stay inside
the existing reserved-suffix warning suppressions.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

…upstream PR electronicarts#595)

The overload taking an EASTL_AssertionFailureFunction set the function
but dropped pContext, so the user's function got a null context. It now
goes through the EASTL_AssertionFailureFunctionEx overload, which stores
the context. GCC reported the dropped parameter with -Wunused-parameter.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

- memory.h: cast the memmove destination to void*, as GCC documents for
  -Wclass-memaccess; the types are trivially copyable.
- vector.h: brace the if constexpr whose body is an assert that may be
  empty (-Wempty-body).
- utility.h, variant.h: mark parameters that are unused for some template
  arguments or configurations EA_MAYBE_UNUSED (-Wunused-parameter and
  -Wunused-but-set-parameter).
- red_black_tree.h, map.h: call a named extract_key instead of a
  temporary, which GCC 13 takes for a dangling reference
  (-Wdangling-reference).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

… GCC

- TestIntrusiveSDList: the failure messages printed c_str() of a string
  temporary that was already destroyed (-Wdangling-pointer).
- TestSegmentedVector: *it == (i < 55) ? 0 : 5 parsed as
  (*it == (i < 55)) ? 0 : 5, so the check didn't test the values
  (-Wint-in-bool-context).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

- Mark results that are only there to check that a call compiles, and
  typedefs of a local iterator class, EA_MAYBE_UNUSED
  (-Wunused-but-set-variable, -Wunused-local-typedefs).
- Leave unused lambda and visitor parameters unnamed (-Wunused-parameter).
- Use size_t loop counters against size_t bounds (-Wsign-compare).
- Parenthesize && inside || (-Wparentheses).
- Initialize enable_shared_from_this explicitly in user copy constructors
  (-Wextra).
- Use a named visitor, which GCC 13 doesn't take for a dangling
  reference (-Wdangling-reference).
- Name the namespace of TestIntrusiveHash's types: with an anonymous one,
  the explicit instantiations leave unused internal-linkage member
  functions (-Wunused-function).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Each suppression covers one function or statement, says why GCC is wrong
there, and is limited to the GCC versions whose warning name exists:

- char_traits.h Compare(const char*): -Wstringop-overread (GCC 11-14) and
  -Wstringop-overflow (GCC 10), bounds the callers have ruled out.
- char_traits.h CharStringUninitializedCopy: -Wstringop-overread (GCC 12-15)
  on reallocation paths that need a longer source than the literal.
- shared_array::unique: -Wuse-after-free (GCC 12) after copy-and-swap.
- radix_sort's final copy: -Wstringop-overflow (GCC 12-15, -O3).
- basic_string::erase: -Wstringop-overflow (GCC 10, -O3).
- fixed_vector_allocator::deallocate: -Wfree-nonheap-object (GCC 12-15);
  it never frees the fixed buffer.
- BitsetBase::set: -Warray-bounds and -Wstringop-overflow (GCC 11, -O3);
  bitset::set checks i < N.

GCC 11 ignores these pragmas for some inlined code, so it still reports
Compare and, at -O3, the fixed_vector deallocation.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

GCC 10 to 15 report null pointers in copy's and move_backward's memmove
specializations when vector::insert inserts into an empty vector: they
come from the branch for ranges that fit in the capacity, which a
non-empty range can't take with a zero capacity. GCC warns before it
folds the condition, so restructuring vector::insert didn't help.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>