# castFrom<SS, ST, TS, TT> method

Converter<TS, TT> castFrom <SS, ST, TS, TT>(Converter<SS, ST> source)

Adapts `source` to be a `Converter<TS, TT>`.

This allows `source` to be used at the new type, but at run-time it must satisfy the requirements of both the new type and its original type.

Conversion input must be both `SS` and `TS` and the output created by `source` for those input must be both `ST` and `TT`.

## Implementation

    static Converter<TS, TT> castFrom<SS, ST, TS, TT>(Converter<SS, ST> source) =>
        new CastConverter<SS, ST, TS, TT>(source);