internal static bool ValidateConstraints(ITypeParameter typeParameter, IType typeArgument, TypeVisitor substitution, CSharpConversions conversions)
{
switch (typeArgument.Kind) // void, null, and pointers cannot be used as type arguments
{
case TypeKind.Void:
case TypeKind.Null:
case TypeKind.Pointer:
return(false);
}
if (typeParameter.HasReferenceTypeConstraint)
{
if (typeArgument.IsReferenceType != true)
{
return(false);
}
}
if (typeParameter.HasValueTypeConstraint)
{
if (!NullableType.IsNonNullableValueType(typeArgument))
{
return(false);
}
}
if (typeParameter.HasDefaultConstructorConstraint)
{
ITypeDefinition def = typeArgument.GetDefinition();
if (def != null && def.IsAbstract)
{
return(false);
}
var ctors = typeArgument.GetConstructors(
m => m.Parameters.Count == 0 && m.Accessibility == Accessibility.Public,
GetMemberOptions.IgnoreInheritedMembers | GetMemberOptions.ReturnMemberDefinitions
);
if (!ctors.Any())
{
return(false);
}
}
foreach (IType constraintType in typeParameter.DirectBaseTypes)
{
IType c = constraintType;
if (substitution != null)
{
c = c.AcceptVisitor(substitution);
}
if (!conversions.IsConstraintConvertible(typeArgument, c))
{
return(false);
}
}
return(true);
}
internal static bool ValidateConstraints(ITypeParameter typeParameter, IType typeArgument, TypeVisitor substitution, CSharpConversions conversions)
{
switch (typeArgument.Kind) { // void, null, and pointers cannot be used as type arguments
case TypeKind.Void:
case TypeKind.Null:
case TypeKind.Pointer:
return false;
}
if (typeParameter.HasReferenceTypeConstraint) {
if (typeArgument.IsReferenceType != true)
return false;
}
if (typeParameter.HasValueTypeConstraint) {
if (!NullableType.IsNonNullableValueType(typeArgument))
return false;
}
if (typeParameter.HasDefaultConstructorConstraint) {
ITypeDefinition def = typeArgument.GetDefinition();
if (def != null && def.IsAbstract)
return false;
var ctors = typeArgument.GetConstructors(
m => m.Parameters.Count == 0 && m.Accessibility == Accessibility.Public,
GetMemberOptions.IgnoreInheritedMembers | GetMemberOptions.ReturnMemberDefinitions
);
if (!ctors.Any())
return false;
}
foreach (IType constraintType in typeParameter.DirectBaseTypes) {
IType c = constraintType;
if (substitution != null)
c = c.AcceptVisitor(substitution);
if (!conversions.IsConstraintConvertible(typeArgument, c))
return false;
}
return true;
}