From 7349dc5cff49cf22c82eb912813e47f30cd7a757 Mon Sep 17 00:00:00 2001 From: Julius Ikkala Date: Sat, 28 Jun 2025 05:39:24 +0300 Subject: Minimal optional constraints (#7422) * Parse optional witness syntax * Allow failing optional constraint * Make `is` work with optional constraint * Allow using optional constraint in checked if statements * Fix tests * Make it work with structs * Fix MSVC build error * Disallow using `as` with optional constraints * Update test to match split is/as errors * Add tests * Fix uninitialized variables in tests * Add tests of incorrect uses & fix related bugs * Mention optional constraints in docs * format code * Fix type unification with NoneWitness * Fix formatting --------- Co-authored-by: slangbot <186143334+slangbot@users.noreply.github.com> Co-authored-by: Nathan V. Morrical --- source/slang/slang-check-overload.cpp | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) (limited to 'source/slang/slang-check-overload.cpp') diff --git a/source/slang/slang-check-overload.cpp b/source/slang/slang-check-overload.cpp index 7a89f2e23..6c0a7f184 100644 --- a/source/slang/slang-check-overload.cpp +++ b/source/slang/slang-check-overload.cpp @@ -994,10 +994,18 @@ bool SemanticsVisitor::TryCheckOverloadCandidateConstraints( auto sup = getSup(m_astBuilder, constraintDeclRef); auto subTypeWitness = tryGetSubtypeWitness(sub, sup); - if (subTypeWitness) + + bool witnessIsOptional = isWitnessUncheckedOptional(subTypeWitness); + bool constraintIsOptional = constraintDecl->hasModifier(); + + if (subTypeWitness && (!witnessIsOptional || constraintIsOptional)) { newArgs.add(subTypeWitness); } + else if (!subTypeWitness && constraintIsOptional) + { + newArgs.add(m_astBuilder->getOrCreate()); + } else { if (context.mode != OverloadResolveContext::Mode::JustTrying) -- cgit v1.2.3