feat: enhance build configuration with C++ standard support and variable substitution

- Added `cxx_standard` field to the build configuration for specifying C++ standards.
- Updated documentation to reflect new `cxx_standard` and variable substitution capabilities in `cflags`, `ldflags`, and `include`.
- Implemented logic to handle C++ standard flags in the build process.
- Modified object file naming to include source file extensions.
- Updated various builder modules to support new language parsing logic.
- Introduced issue and feature request templates for better community engagement.

src/core/builder/common.rs

@@ -262,7 +262,22 @@ pub fn object_path(obj_dir: &Path, source: &str, obj_ext: &str) -> String {
         stripped.to_path_buf()
     };
     let mut out = obj_dir.join(rel);
-    out.set_extension(obj_ext.trim_start_matches('.'));
+    let ext = out
+        .extension()
+        .and_then(|e| e.to_str())
+        .unwrap_or("")
+        .to_string();
+    let obj_ext = obj_ext.trim_start_matches('.');
+    if !ext.is_empty() {
+        let stem = out
+            .file_stem()
+            .and_then(|s| s.to_str())
+            .unwrap_or("")
+            .to_string();
+        out.set_file_name(format!("{stem}.{ext}.{obj_ext}"));
+    } else {
+        out.set_extension(obj_ext);
+    }
     out.to_string_lossy().to_string()
 }
 
@@ -379,28 +394,28 @@ mod tests {
     fn object_path_basic() {
         let obj_dir = Path::new("target/debug/obj");
         let result = object_path(obj_dir, "./src/main.c", "o");
-        assert_eq!(result, "target/debug/obj/main.o");
+        assert_eq!(result, "target/debug/obj/main.c.o");
     }
 
     #[test]
     fn object_path_nested() {
         let obj_dir = Path::new("target/debug/obj");
         let result = object_path(obj_dir, "./src/core/utils.c", "o");
-        assert_eq!(result, "target/debug/obj/core/utils.o");
+        assert_eq!(result, "target/debug/obj/core/utils.c.o");
     }
 
     #[test]
     fn object_path_no_prefix() {
         let obj_dir = Path::new("target/debug/obj");
         let result = object_path(obj_dir, "src/main.c", "o");
-        assert_eq!(result, "target/debug/obj/main.o");
+        assert_eq!(result, "target/debug/obj/main.c.o");
     }
 
     #[test]
     fn object_path_msvc_ext() {
         let obj_dir = Path::new("target/debug/obj");
         let result = object_path(obj_dir, "./src/main.c", "obj");
-        assert_eq!(result, "target/debug/obj/main.obj");
+        assert_eq!(result, "target/debug/obj/main.c.obj");
     }
 
     #[test]

src/core/builder/gas.rs

@@ -25,7 +25,7 @@ use std::time::Instant;
 
 pub fn build(ctx: &BuildContext) -> Result<f64, String> {
     let lang = ctx.language.to_lowercase();
-    if lang.split('+').any(|p| p.trim() != "asm") {
+    if lang.split(',').any(|p| p.trim() != "asm") {
         return Err("GAS backend requires build.language = \"asm\"".to_string());
     }
     let assembler = if ctx.compiler.is_empty() {

src/core/builder/mod.rs

@@ -27,7 +27,7 @@ pub struct BuildContext<'a> {
     pub compiler: &'a str,
     pub language: &'a str,
     pub standard: &'a str,
-    #[allow(dead_code)]
+    pub cxx_standard: &'a str,
     pub target: Option<&'a str>,
     pub target_dir: Option<&'a str>,
     pub kind: &'a str,

src/core/builder/msvc.rs

@@ -144,8 +144,8 @@ pub(crate) fn collect_sources(ctx: &BuildContext) -> Result<Vec<String>, String>
 
 fn source_extensions(language: &str) -> Vec<&str> {
     let mut out = Vec::new();
-    for part in language.split('+') {
-        let lang = part.trim().to_lowercase();
+    for part in language.split(',').map(|s| s.trim()) {
+        let lang = part.to_lowercase();
         match lang.as_str() {
             "c" => out.extend(["c"]),
             "c++" | "cpp" | "cxx" => out.extend(["cpp", "cxx", "cc"]),
@@ -243,18 +243,26 @@ fn build_object(
     let mut cmd = Command::new(compiler);
     cmd.arg("/nologo");
 
-    match ctx.language.to_lowercase().as_str() {
-        "c" => {
-            cmd.arg("/TC");
-        }
-        "c++" | "cpp" | "cxx" => {
-            cmd.arg("/TP");
-        }
-        _ => return Err("Unsupported language".to_string()),
+    let ext = Path::new(source)
+        .extension()
+        .and_then(|e| e.to_str())
+        .unwrap_or("");
+    let is_cpp = matches!(ext, "cpp" | "cxx" | "cc");
+    if is_cpp {
+        cmd.arg("/TP");
+    } else {
+        cmd.arg("/TC");
     }
 
-    if !ctx.standard.is_empty() && ctx.language.to_lowercase() != "asm" {
-        let std_flag = msvc_standard_flag(ctx.language, ctx.standard)?;
+    let std_val = if is_cpp && !ctx.cxx_standard.is_empty() {
+        ctx.cxx_standard
+    } else if !is_cpp && !ctx.standard.is_empty() {
+        ctx.standard
+    } else {
+        ""
+    };
+    if !std_val.is_empty() {
+        let std_flag = msvc_standard_flag(if is_cpp { "c++" } else { "c" }, std_val)?;
         cmd.arg(std_flag);
     }
 

src/core/builder/nasm.rs

@@ -25,7 +25,7 @@ use std::time::Instant;
 
 pub fn build(ctx: &BuildContext) -> Result<f64, String> {
     let lang = ctx.language.to_lowercase();
-    if lang.split('+').any(|p| p.trim() != "asm") {
+    if lang.split(',').any(|p| p.trim() != "asm") {
         return Err("NASM backend requires build.language = \"asm\"".to_string());
     }
     let assembler = if ctx.compiler.is_empty() {

src/core/builder/unix_cc.rs

@@ -133,8 +133,8 @@ pub(crate) fn collect_sources(ctx: &BuildContext) -> Result<Vec<String>, String>
 
 fn source_extensions(language: &str) -> Vec<&str> {
     let mut out = Vec::new();
-    for part in language.split('+') {
-        let lang = part.trim().to_lowercase();
+    for part in language.split(',').map(|s| s.trim()) {
+        let lang = part.to_lowercase();
         match lang.as_str() {
             "c" => out.extend(["c"]),
             "c++" | "cpp" | "cxx" => out.extend(["cpp", "cxx", "cc"]),
@@ -210,16 +210,18 @@ fn build_object(
     }
 
     let mut cmd = Command::new(compiler);
-    cmd.arg("-c").arg(source).arg("-o").arg(obj_path);
-
-    if ctx.kind == "sharedlib" {
-        cmd.arg("-fPIC");
-    }
+    cmd.arg("-c");
 
     if let Some(flag) = asm_lang_flag(source) {
         cmd.arg("-x").arg(flag);
     }
 
+    cmd.arg(source).arg("-o").arg(obj_path);
+
+    if ctx.kind == "sharedlib" {
+        cmd.arg("-fPIC");
+    }
+
     if let Some(platform) = ctx.platform
         && !platform.trim().is_empty()
     {
@@ -227,7 +229,16 @@ fn build_object(
     }
 
     if !ctx.standard.is_empty() && ctx.language.to_lowercase() != "asm" {
-        cmd.arg(format!("-std={}", ctx.standard));
+        let ext = Path::new(source)
+            .extension()
+            .and_then(|e| e.to_str())
+            .unwrap_or("");
+        let is_cpp = matches!(ext, "cpp" | "cxx" | "cc");
+        if is_cpp && !ctx.cxx_standard.is_empty() {
+            cmd.arg(format!("-std={}", ctx.cxx_standard));
+        } else if !is_cpp {
+            cmd.arg(format!("-std={}", ctx.standard));
+        }
     }
 
     let use_dcr_defaults = ctx.cflags.is_empty() && !is_bare_metal_target(ctx.target);