Improve C++ compound-assignment operator and C compound literal support#824
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tannergooding merged 3 commits intoJul 18, 2026
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Projects operator+=, -=, *=, /=, %=, &=, |=, ^=, <<=, >>= to op_AdditionAssignment and friends, consistent with the existing operator= to op_Assign mapping. Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>
A C compound literal (T){ ... } has no distinct C# spelling, so it projects as the object initializer emitted by its inner initializer list.
Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>
…argeting latest When generating latest code, a C++ compound-assignment operator that returns a pointer/reference to its declaring type and just returns \ his\/\*this\ is projected onto a C# 14 user-defined \operator +=\ with a void return, dropping the trailing return, rather than the \op_*Assignment\ metadata-name projection. Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>
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Maps C++ compound-assignment operators to their .NET metadata names so they project into C# instead of being skipped.
operator+=becomesop_AdditionAssignment,operator<<=becomesop_LeftShiftAssignment, and so on -- consistent with howoperator=is already emitted asop_Assign.Fixes #821
When generating
latestcode (.NET 10 / C# 14 currently), a compound-assignment operator is instead projected onto the new C# 14 user-defined compound-assignment operator feature. This is only safe for an instance member that returns a pointer/reference to its declaring type and whose body just returnsthis/*this, so the transform is gated on exactly that: the return type is dropped tovoid, the trailing return is elided, and the result ispublic void operator +=(MyStruct rhs) { ... }.An operator that returns something other than
this(e.g. a parameter) does not qualify and continues to emit under itsop_*Assignmentmetadata name -- covered by a regression case inCompoundAssignmentOperatorTest.Emits C compound literals (
(MyStruct){ .x = 1 }) as C# object initializers rather than dropping them.Fixes #819