[BUG]`hero.Resulthandler` can only handle custom struct about iris

[dydhyhwu]

related code:

iris/hero/func_result.go

Lines 264 to 331 in b904793

	switch value := f.(type) {
	case bool:
	found = value
	if !found {
	// skip everything, skip other values, we don't care about other return values,
	// this boolean is the higher in order.
	break
	}
	case int:
	statusCode = value
	case string:
	// a string is content type when it contains a slash and
	// content or custom struct is being calculated already;
	// (string -> content, string-> content type)
	// (customStruct, string -> content type)
	if (len(content) > 0 || custom != nil) && strings.IndexByte(value, slashB) > 0 {
	contentType = value
	} else {
	// otherwise is content
	contentType = context.ContentTextHeaderValue
	content = []byte(value)
	}
	case []byte:
	// it's raw content, get the latest
	content = value
	case compatibleErr:
	if value == nil || isNil(v) {
	continue
	}
	if statusCode < 400 && value != ErrStopExecution {
	statusCode = DefaultErrStatusCode
	}
	ctx.StatusCode(statusCode)
	return value
	default:
	// else it's a custom struct or a dispatcher, we'll decide later
	// because content type and status code matters
	// do that check in order to be able to correctly dispatch:
	// (customStruct, error) -> customStruct filled and error is nil
	if custom == nil {
	// if it's a pointer to struct/map.
	if isNil(v) {
	// if just a ptr to struct with no content type given
	// then try to get the previous response writer's content type,
	// and if that is empty too then force-it to application/json
	// as the default content type we use for structs/maps.
	if contentType == "" {
	contentType = ctx.GetContentType()
	if contentType == "" {
	contentType = context.ContentJSONHeaderValue
	}
	}
	continue
	}
	if value != nil {
	custom = value // content type will be take care later on.
	}
	}
	}
	}
	return dispatchCommon(ctx, statusCode, contentType, content, custom, handler, found)

iris/hero/func_result.go

Lines 366 to 373 in b904793

	if v != nil {
	return handler(ctx, v)
	}
	// .Write even len(content) == 0 , this should be called in order to call the internal tryWriteHeader,
	// it will not cost anything.
	_, err := ctx.Write(content)
	return err

[dydhyhwu]

@kataras need some help