style: opt_value style

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "rust_util"
-version = "0.6.16"
+version = "0.6.17"
 authors = ["Hatter Jiang <jht5945@gmail.com>"]
 edition = "2018"
 description = "Hatter's Rust Util"

src/lib.rs

@@ -34,6 +34,9 @@ pub mod util_net;
 #[macro_export] macro_rules! debugging {
     ($($arg:tt)+) => ( rust_util::util_msg::print_debug(&format!($($arg)+)); )
 }
+#[macro_export] macro_rules! opt_value {
+    ($e: expr) => ( match $e { Some(o) => o, None => return, } )
+}
 
 pub type XResult<T> = Result<T, Box<dyn std::error::Error>>;