Rust.md

@@ -96,5 +96,53 @@ $3634400
 
 ### Icon for windows exe
 
-https://stackoverflow.com/a/76500197
+MinGW-w64 (例: MingW-W64-builds) の bin にパスを通しておく必要がある。
+
+[Cargo.toml]
+```toml
+[package]
+...
+build = "build.rs"
+```
 
+[build.rs]
+```rs
+use std::{
+    env,
+    fs::{copy, write},
+    path::PathBuf,
+    process::Command,
+};
+
+fn main() {
+    if env::var("CARGO_CFG_TARGET_OS").unwrap() == "windows" {
+        let project_dir = PathBuf::from(
+            env::var("CARGO_MANIFEST_DIR")
+                .expect("environment variable 'CARGO_MANIFEST_DIR' is not set"),
+        );
+        let out_dir_str = env::var("OUT_DIR").expect("environment variable 'OUT_DIR' is not set");
+        let out_dir = PathBuf::from(&out_dir_str);
+
+        copy(
+            project_dir.join("res").join("icon.ico"),
+            out_dir.join("icon.ico"),
+        )
+        .expect("failed to copy 'res/icon.icon' file to out directory");
+        write(out_dir.join("icon.rc"), "1 ICON icon.ico")
+            .expect("failed to write 'icon.rc' file to out directory");
+
+        Command::new("windres")
+            .current_dir(&out_dir)
+            .arg("icon.rc")
+            .arg("icon.lib")
+            .spawn()
+            .expect("failed to create 'icon.lib' using 'windres'");
+
+        println!("cargo:rustc-link-search={}", out_dir_str);
+        println!("cargo:rustc-link-lib=icon");
+    }
+}
+```
+
+参考:\
+https://stackoverflow.com/a/76500197