MAUI uses implicit operators invoked via reflection in several places, for example:

• BindableProperty.TryConvert(...)
  • this codepath is not only used in bindings, but also when BindableObject.SetValue(...) is used
• StaticResourceExtension.ProvideValue(...)

Unfortunately, this pattern isn't trimming/AOT compatible and we cannot fix it with [DynamicallyAccessedMembers] (in some cases the type isn't known at compile time, such as in value.GetType().GetImplicitConversionOperator(...)). When app code is trimmed, some of the required implicit conversion operators might not be available at runtime leading to unexpected behavior.

Related to #18658, /cc @jonathanpeppers
Trimming warnings related to this issue are tracked in #19397

Possible solutions

1. Make the use of implicit operators obsolete and replace them with a different mechanism, such as IValueConverter
   • we could still keep the existing code with implicit operators, but it would be the responsibility of the developers to ensure the implicit operators are preserved by the trimmer using [Preserve] or [DynamicDependency]
   • this would be a breaking change to some apps
2. Globally disable trimming of implicit operators
   • this issue is very similar to an issue in System.Linq.Expressions - see Change trimming workaround for Linq.Expressions usage of custom operators runtime#79016 - cc @vitek-karas
   • if the discussed changes were implemented in the trimmer, we could use the new APIs to resolve this issue