Add support for adding "using namespace" statements

src/bindgen/bindings.rs

@@ -217,6 +217,14 @@ impl Bindings {
             }
 
             if self.config.language == Language::Cxx || self.config.cpp_compat {
+                if let Some(ref using) = self.config.using {
+                    for namespace in using {
+                        out.new_line();
+                        write!(out, "using namespace {};", namespace);
+                    }
+                    out.new_line();
+                }
+
                 out.new_line();
                 out.write("extern \"C\" {");
                 out.new_line();

src/bindgen/config.rs

@@ -621,6 +621,8 @@ pub struct Config {
     pub namespace: Option<String>,
     /// An optional list of namespaces. Only applicable when language="C++"
     pub namespaces: Option<Vec<String>>,
+    /// An optional list of namespaces to ddeclare as using. Only applicable when language="C++"
+    pub using: Option<Vec<String>>,
     /// The style to use for braces
     pub braces: Braces,
     /// The preferred length of a line, used for auto breaking function arguments
@@ -672,6 +674,7 @@ impl Default for Config {
             no_includes: false,
             namespace: None,
             namespaces: None,
+            using: None,
             braces: Braces::SameLine,
             line_length: 100,
             tab_width: 2,

tests/expectations/both/using.c

@@ -0,0 +1,6 @@
+#include <stdarg.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdlib.h>
+
+void root(void);

tests/expectations/both/using.compat.c

@@ -0,0 +1,16 @@
+#include <stdarg.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdlib.h>
+
+#ifdef __cplusplus
+using namespace std;
+
+extern "C" {
+#endif // __cplusplus
+
+void root(void);
+
+#ifdef __cplusplus
+} // extern "C"
+#endif // __cplusplus

tests/expectations/tag/using.c

@@ -0,0 +1,6 @@
+#include <stdarg.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdlib.h>
+
+void root(void);

tests/expectations/tag/using.compat.c

@@ -0,0 +1,16 @@
+#include <stdarg.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdlib.h>
+
+#ifdef __cplusplus
+using namespace std;
+
+extern "C" {
+#endif // __cplusplus
+
+void root(void);
+
+#ifdef __cplusplus
+} // extern "C"
+#endif // __cplusplus

tests/expectations/using.c

@@ -0,0 +1,6 @@
+#include <stdarg.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdlib.h>
+
+void root(void);

tests/expectations/using.compat.c

@@ -0,0 +1,16 @@
+#include <stdarg.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdlib.h>
+
+#ifdef __cplusplus
+using namespace std;
+
+extern "C" {
+#endif // __cplusplus
+
+void root(void);
+
+#ifdef __cplusplus
+} // extern "C"
+#endif // __cplusplus

tests/expectations/using.cpp

@@ -0,0 +1,12 @@
+#include <cstdarg>
+#include <cstdint>
+#include <cstdlib>
+#include <new>
+
+using namespace std;
+
+extern "C" {
+
+void root();
+
+} // extern "C"

tests/rust/using.rs

@@ -0,0 +1,3 @@
+#[no_mangle]
+pub extern "C" fn root() {
+}

tests/rust/using.toml

@@ -0,0 +1 @@
+using = ["std"]