Add String Conversion Function

Examples/C/Main.c

@@ -4,6 +4,16 @@
 
 int main()
 {
+    // Hello
+
+    char *result = Hello("C");
+
+    printf("%s\n", result);
+
+    DeallocString(result);
+
+    // Operations
+
     int num1 = 1;
     int num2 = 2;
 

Examples/CSharp/Main.cs

@@ -11,6 +11,9 @@ namespace CSharp
             const string Library = "libLibrary";
         #endif
 
+        [DllImport(Library)]
+        static extern string Hello(string input);
+
         [DllImport(Library)]
         static extern float Add(float Num1, float Num2);
 
@@ -25,6 +28,14 @@ namespace CSharp
 
         static void Main(string[] args)
         {
+            // Hello
+
+            string result = Hello("C#");
+
+            Console.WriteLine(result);
+
+            // Operations
+
             int num1 = 1;
             int num2 = 2;
 

Examples/Cpp/Main.cpp

@@ -6,6 +6,15 @@ using namespace std;
 
 int main()
 {
+    // Hello
+    char *result = Library::Hello("C++");
+
+    cout << result << "\n";
+
+    Library::DeallocString(result);
+
+    // Operations
+
     int num1 = 1;
     int num2 = 2;
 

Source/Allocator.rs

@@ -0,0 +1,12 @@
+use libc::c_char;
+use std::ffi::CString;
+
+#[no_mangle]
+/// Dealloc a string pointer.
+pub extern "C" fn DeallocString(ptr: *mut c_char) {
+    if ptr.is_null() {
+        return;
+    }
+
+    unsafe { CString::from_raw(ptr) };
+}

Source/Converter.rs

@@ -0,0 +1,14 @@
+use libc::c_char;
+use std::ffi::{CStr, CString};
+
+/// Convert C string to Rust String.
+pub fn ToString(ptr: *mut c_char) -> String {
+    let input = unsafe { CStr::from_ptr(ptr) };
+
+    return input.to_str().unwrap().to_string();
+}
+
+/// Convert Rust String to C string.
+pub fn FromString(string: String) -> *mut c_char {
+    return CString::new(string).unwrap().into_raw();
+}

Source/Library.h

@@ -18,8 +18,15 @@ namespace Library
 
         float Add(float num1, float num2);
 
+        /**
+         * Dealloc a string pointer.
+         */
+        void DeallocString(char *ptr);
+
         float Divide(float num1, float num2);
 
+        char *Hello(char *input);
+
         float Multiply(float num1, float num2);
 
         float Subtract(float num1, float num2);

Source/Library.rs

@@ -1,5 +1,17 @@
 #![allow(non_snake_case)]
 
+mod Allocator;
+mod Converter;
+
+use libc::c_char;
+
+#[no_mangle]
+pub extern "C" fn Hello(input: *mut c_char) -> *mut c_char {
+    let output = format!("Hello {}", Converter::ToString(input));
+
+    return Converter::FromString(output);
+}
+
 #[no_mangle]
 pub extern "C" fn Add(num1: f32, num2: f32) -> f32 {
     return num1 + num2;