## Can Go Slice Types be Converted Directly? The Case of []Foo and []Bar.

Issue: Conversion Between Slice Types

The inability to convert between slice types, as demonstrated with []Foo and []Bar, has raised a question regarding the runtime overhead and potential compiler optimizations.

Reason for Limited Conversion:

The type conversion []Bar(foos) attempts to assign a type with a different underlying type to a variable of another type. According to the Go specification, type conversions are only allowed when specific criteria are met, such as when the underlying types are identical.

Underlying Type Discrepancy:

While Foo and Bar have the same underlying type, this does not extend to slices created from these types. The underlying type of []Foo is distinct from that of []Bar. Therefore, assigning []Foo to []Bar violates the type conversion rules.

Compiler Aliasing Suggestion:

The proposal to have the compiler treat Bar as an alias of Foo would introduce consistency in the underlying types. However, this approach is not practical in Go due to the strict adherence to type safety.

Allowing such aliasing would undermine the integrity of the type system. Variables of one type could be silently assigned values of another type, potentially leading to unexpected behavior and runtime errors.

Alternative Approach:

Instead of aliasing types, a more idiomatic solution is to define a wrapper type, such as Foos. This type can be a slice of Foo, but it is distinguishable from []Foo. Similarly, Bars can be defined as a slice of Foos.

By introducing these wrapper types, the program can safely convert between Foos and Bars, as they share the same underlying element type.

The above is the detailed content of ## Can Go Slice Types be Converted Directly? The Case of []Foo and []Bar.. For more information, please follow other related articles on the PHP Chinese website!