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GD0301: The generic type argument must be a Variant compatible type¶
Rule ID |
GD0301 |
Category |
Usage |
Fix is breaking or non-breaking |
Breaking |
Enabled by default |
Yes |
Cause¶
An unsupported type is specified for a generic type argument when a Variant-compatible type is expected.
Rule description¶
When a generic type parameter is annotated with the [MustBeVariant] attribute,
the generic type is required to be a Variant-compatible type. For example,
the generic Godot.Collections.Array<T> type only supports items of a type
that can be converted to Variant.
class SomeType { }
// SomeType is not a valid type because it doesn't derive from GodotObject,
// so it's not compatible with Variant.
var invalidArray = new Godot.Collections.Array<SomeType>();
// System.Int32 is a valid type because it's compatible with Variant.
var validArray = new Godot.Collections.Array<int>();
How to fix violations¶
To fix a violation of this rule, change the generic type argument to be a Variant-compatible type or use a different API that doesn't require the generic type argument to be a Variant-compatible type.
When to suppress warnings¶
Do not suppress a warning from this rule. API that contains generic type arguments
annotated with the [MustBeVariant] attribute usually has this requirement
because the values will be passed to the engine, if the type can't be marshalled
it will result in runtime errors.