public static bool TryGetElementTypesIfTupleOrCompatible(this TypeSymbol type, out ImmutableArray <TypeSymbol> elementTypes)
{
if (type.IsTupleType)
{
elementTypes = ((TupleTypeSymbol)type).TupleElementTypes;
return(true);
}
// The following codepath should be very uncommon since it would be rare
// to see a tuple underlying type not represented as a tuple.
// It still might happen since tuple underlying types are creatable via public APIs
// and it is also possible that they would be passed in.
// PERF: if allocations here become nuisance, consider caching the results
// in the type symbols that can actually be tuple compatible
int cardinality;
if (!type.IsTupleCompatible(out cardinality))
{
// source not a tuple or compatible
elementTypes = default(ImmutableArray <TypeSymbol>);
return(false);
}
var elementTypesBuilder = ArrayBuilder <TypeSymbol> .GetInstance(cardinality);
TupleTypeSymbol.AddElementTypes((NamedTypeSymbol)type, elementTypesBuilder);
Debug.Assert(elementTypesBuilder.Count == cardinality);
elementTypes = elementTypesBuilder.ToImmutableAndFree();
return(true);
}
/// <summary>
/// Same as <see cref="SubstituteType"/>, but with special behavior around tuples.
/// In particular, if substitution makes type tuple compatible, transform it into a tuple type.
/// </summary>
internal TypeWithModifiers SubstituteTypeWithTupleUnification(TypeSymbol previous)
{
TypeWithModifiers result = SubstituteType(previous);
// Make it a tuple if it became compatible with one.
if ((object)result.Type != null && !previous.IsTupleCompatible())
{
var possiblyTuple = TupleTypeSymbol.TransformToTupleIfCompatible(result.Type);
if ((object)result.Type != possiblyTuple)
{
result = new TypeWithModifiers(possiblyTuple, result.CustomModifiers);
}
}
return(result);
}
public static ImmutableArray <TypeSymbol> GetElementTypesOfTupleOrCompatible(this TypeSymbol type)
{
if (type.IsTupleType)
{
return(((TupleTypeSymbol)type).TupleElementTypes);
}
// The following codepath should be very uncommon since it would be rare
// to see a tuple underlying type not represented as a tuple.
// It still might happen since tuple underlying types are creatable via public APIs
// and it is also possible that they would be passed in.
Debug.Assert(type.IsTupleCompatible());
// PERF: if allocations here become nuisance, consider caching the results
// in the type symbols that can actually be tuple compatible
var elementTypesBuilder = ArrayBuilder <TypeSymbol> .GetInstance();
TupleTypeSymbol.AddElementTypes((NamedTypeSymbol)type, elementTypesBuilder);
return(elementTypesBuilder.ToImmutableAndFree());
}
/// <summary>
/// Same as <see cref="SubstituteType"/>, but with special behavior around tuples.
/// In particular, if substitution makes type tuple compatible, transform it into a tuple type.
/// </summary>
internal TypeWithModifiers SubstituteTypeWithTupleUnification(TypeSymbol previous)
{
TypeWithModifiers result = SubstituteType(previous);
// Make it a tuple if it became compatible with one.
if ((object)result.Type != null && !previous.IsTupleCompatible())
{
var possiblyTuple = TupleTypeSymbol.TransformToTupleIfCompatible(result.Type);
if ((object)result.Type != possiblyTuple)
{
result = new TypeWithModifiers(possiblyTuple, result.CustomModifiers);
}
}
return result;
}
