Note: #1025 seems required as well to build on MSVC 14.5+. This change was tested on top of 1025.

Fix Point.cpp compilation error on modern MSVC toolsets

1. What has been changed

Change #1: Fixed missing closing brace

• Line 108: Added missing } to close the second lambda in distanceSquared sol::overload

Change #2: Separated C and C++ linkage

• Extracted Lua binding registration logic into new register_el_Point(lua_State* L) function
• Made luaopen_el_Point() a thin wrapper that calls register_el_Point()
• Added explanatory comment about MSVC toolset behavior

2. Why it has been changed / Points addressed

Compilation failure on MSVC 14.5+:

error C2526: 'luaopen_el_Point::<lambda_8>::<lambda_invoker_vectorcall>': 
C linkage function cannot return C++ class 'juce::Point<double>'

Modern MSVC toolsets (14.5+) enforce stricter C++20 linkage rules. The lambda with explicit return type -> PTF inside the extern "C" function luaopen_el_Point() was being interpreted as having C linkage itself, which cannot return C++ class types.

The missing brace caused cascading parse errors that made the root cause harder to identify initially.

6. Impact on cross-platform compatibility

Windows MSVC:

• ✅ Fixes build on MSVC 14.5+ (Visual Studio 2025/2026 preview toolsets)
• ✅ Should remain compatible with older MSVC versions (tested with all 33 tests passing)

Other platforms:

• No impact on older compiler versions - the wrapper pattern should be universally compatible C++

This appears to be a Windows-specific issue where newer MSVC is correctly enforcing standards compliance that other compilers may handle more leniently.

9. Alternative approaches considered

Option A: Remove explicit return type (not taken)

"rotated", [](PTF& self, lua_Number angle) {  // No -> PTF
    return self.rotatedAboutOrigin(angle);
}

• Simpler, minimal change
• Less explicit about return type
• Could work but doesn't address the underlying linkage issue as clearly

Option B: Wrapper function (taken)

• More code but clearer separation of concerns
• Documents the issue for future maintainers
• Follows similar patterns seen in other Lua binding files
• Allows keeping explicit return type for documentation

10. Test recommendations

All existing tests pass (33/33). Specific validation:

• ✅ Build succeeds on MSVC 14.5+
• ✅ All Point.cpp Lua bindings functional
• ✅ No runtime behavior changes observed

Recommended additional testing:

• Verify Point.lua bindings work correctly in Element's Lua scripting environment
• Test rotated() method specifically since that was the lambda triggering the error

11. Open Issues / Things to critically consider

Consistency across codebase:
Other luaopen_* functions in src/el/ may have similar patterns with lambdas inside extern "C" functions. I did not encounter build errors from those files, but they might be worth reviewing for consistency or potential future issues on even stricter compilers.