add: postopenapiof codegen

codegen/postopenapiof/main.go

@@ -0,0 +1,51 @@
+package main
+
+import (
+	"os"
+	"strings"
+)
+
+const head = `// Code generated by codegen/postopenapiof. DO NOT EDIT.
+
+package nano
+
+import (
+	"io"
+	"unsafe"
+
+	"github.com/pkg/errors"
+)
+`
+
+const template = `
+func (bot *Bot) postOpenAPIof[T any](ep string, body io.Reader) (*[T any], error) {
+	resp := &struct {
+		CodeMessageBase
+		[T any]
+	}{}
+	err := bot.PostOpenAPI(ep, resp, body)
+	if err != nil {
+		err = errors.Wrap(err, getCallerFuncName())
+		return nil, err
+	}
+	return (*[T any])(unsafe.Add(unsafe.Pointer(resp), unsafe.Sizeof(CodeMessageBase{}))), nil
+}
+`
+
+func main() {
+	f, err := os.Create("openapi_codegen_postopenapiof.go")
+	if err != nil {
+		panic(err)
+	}
+	defer f.Close()
+	_, err = f.WriteString(head)
+	if err != nil {
+		panic(err)
+	}
+	for _, name := range os.Args[1:] {
+		_, err = f.WriteString(strings.ReplaceAll(template, "[T any]", name))
+		if err != nil {
+			panic(err)
+		}
+	}
+}