internal static ConversionSymbol ResolveByRefConversion(Expr expr, TypeSymbol type, BindOptions options)
{
if (type.IsByRef && TypesMatch(expr.Datatype, type.ElementType))
{
return(ConversionSymbol.CreateByRef());
}
else
{
var inner = ConversionSymbol.Create(ConversionKind.Deref);
var outer = Conversion(TypeConversion.Bound(expr, expr.Datatype.ElementType, inner), type, options);
if (outer.Exists)
{
return(ConversionSymbol.Create(outer, inner));
}
}
return(null);
}
internal static ConversionSymbol ResolveUsualConversion(Expr expr, TypeSymbol type, BindOptions options)
{
if (expr.Datatype.NativeType == NativeType.Usual)
{
if (type.NativeType == NativeType.Object)
{
if (options.HasFlag(BindOptions.BoxUsual))
{
return(ConversionSymbol.Create(ConversionKind.Boxing));
}
else
{
MethodSymbol converter = null;
ResolveConversionMethod(expr, type, Compilation.Get(NativeType.Usual).Lookup(XSharpFunctionNames.ToObject), ref converter, options);
if (converter != null)
{
return(ConversionSymbol.Create(ConversionKind.ImplicitUserDefined, converter));
}
}
}
else if (type.IsByRef)
{
var elem = type.ElementType;
var inner = Conversion(expr, elem, options);
if (inner.Exists)
{
if (expr.Symbol.HasRefAccess && inner.Kind == ConversionKind.Identity)
{
return(ConversionSymbol.CreateByRef());
}
else
{
var outer = ConversionSymbol.CreateByRef();
return(ConversionSymbol.Create(outer, new ConversionToTemp(inner, elem)));
}
}
}
else
{
MethodSymbol converter = null;
ResolveConversionMethod(expr, Compilation.Get(NativeType.Object), Compilation.Get(NativeType.Usual).Lookup(XSharpFunctionNames.ToObject), ref converter, options);
if (converter != null)
{
var inner = ConversionSymbol.Create(ConversionKind.ImplicitUserDefined, converter);
var outer = type.IsReferenceType ? ConversionSymbol.Create(ConversionKind.ExplicitReference)
: type.IsValueType ? ConversionSymbol.Create(ConversionKind.Unboxing)
: ConversionSymbol.Create(ConversionKind.NoConversion);
if (outer.Exists)
{
return(ConversionSymbol.Create(outer, inner));
}
}
}
}
else if (type.NativeType == NativeType.Usual && expr.Datatype.IsReferenceType) // XXX dead code!
{
var inner = Conversion(expr, Compilation.Get(NativeType.Object), options | BindOptions.Explicit);
if (inner.Exists)
{
var outer = Conversion(TypeConversion.Bound(expr, Compilation.Get(NativeType.Object), inner), type, options);
if (outer.Exists)
{
return(ConversionSymbol.Create(outer, inner));
}
}
}
return(null);
}