Type Alias AssertTypeStrong<T, D>

AssertTypeStrong: D extends T ? T : ThrowErrorOnInstantiation<T>

Assert that a type is strongly assignable to another type.

Type Parameters

T extends D
The inferred or concrete type to validate
D
The expected destination type

Remarks

This is a strict compile-time check that T is exactly assignable to D. If T is not assignable to D, or if D is not assignable to T, this will produce a compiler error.

Hack: This type uses recursive conditional types to force TypeScript to evaluate the types fully, causing an error to be thrown if the assertion fails.

Example

type A = AssertTypeStrong< true, true >;               // ✓
type B = AssertTypeStrong< true, boolean >;            // ✗ TS error
type C = AssertTypeStrong< string, string | number >;  // ✗ TS error

Type Alias AssertTypeStrong<T, D>

Type Parameters

Remarks

Example

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