Simplify generic usage on method types

[Retro64]

Is your feature request related to a problem? Please describe.

Currently, the types describing the methods are using three parameters (see https://github.com/axios/axios/blob/master/index.d.ts#L177)

get<T = any, R = AxiosResponse<T>, D = any>(url: string, config?: AxiosRequestConfig<D>): Promise<R>;

At least from my point of view, the second parameter does not bring in any additional value, as it is not really configurable, but simply relies on the first parameter.

Describe the solution you'd like

Bringing in the AxiosResponse to the return type, would end in a cleaner interface, only defined by input and returned type (in fact type of Promise of AxiosResponse):

get<T = any, D = any>(url: string, config?: AxiosRequestConfig<D>): Promise<AxiosResponse<T>>;

Describe alternatives you've considered

For sure, the type can be kept this way, but brings in some mental overhead and no benefit in defining the second generic parameter.

Additional context

I know this might be a breaking change, but I guess it brings in more clarity on the interface, simply dependent from input and output types.

[Retro64]

Addition:

from my point of view, even

get<T, D>(url: string, config?: AxiosRequestConfig<D>): Promise<AxiosResponse<T>>;

should work out and resolve #4141 and the root cause of #4142 , as the type should be inferred by the compiler (see last passages of https://www.typescriptlang.org/docs/handbook/2/generics.html#hello-world-of-generics ).

[dietergeerts]

Why is this closed? Will this be considered in future releases, or will this just not be implemented? Currently, to type the body, we need to add the second type param each time, which should not be needed.