public InstanceProvider?GetInstanceProvider(TypeInfo forType)
{
var paired = GetPairedType(forType, DESERIALIZER_KIND);
if (paired == null)
{
return(null);
}
var instanceMtd = paired.GetMethodNonNull("__InstanceProvider", PublicStatic);
#pragma warning disable CS0618 // This obsolete to prevent clients from using them, but they are fine for us.
var forConstructorAttrs = instanceMtd.GetCustomAttributes <ConstructorInstanceProviderAttribute>();
#pragma warning restore CS0618
if (forConstructorAttrs.Any())
{
var consOnTypes = forConstructorAttrs.Select(x => x.ForType).Distinct().ToImmutableArray();
if (consOnTypes.Length > 1)
{
Throw.ImpossibleException($"Generated type {paired} (for {forType}) claims multiple constructors for an InstanceProvider.");
}
var consOnType = consOnTypes.Single();
var consParams = forConstructorAttrs.OrderBy(x => x.ParameterIndex).Select(i => i.ParameterType).ToArray();
var cons = consOnType.GetConstructor(AllInstance, null, consParams, null);
if (cons == null)
{
Throw.ImpossibleException($"Generated type {paired} (for {forType}) claims a constructor for an InstanceProvider that could not be found.");
}
return(InstanceProvider.ForConstructorWithParametersInner(cons, paired));
}
return(InstanceProvider.ForMethodInner(instanceMtd, paired));
}
