Improving basic commands

src/basic/string16.cpp

@@ -249,6 +249,14 @@ String16 Copy16(Allocator allocator, char16_t *string) {
     return Copy(allocator, s);
 }
 
+String16 Concat(Allocator allocator, String16 a, String16 b) {
+    char16_t *str = AllocArray(allocator, char16_t, a.len + b.len + 1);
+    MemoryCopy(str, a.data, a.len * 2);
+    MemoryCopy(str + a.len, b.data, b.len * 2);
+    str[a.len + b.len] = 0;
+    return {str, a.len + b.len};
+}
+
 void NormalizePathInPlace(String16 s) {
     for (int64_t i = 0; i < s.len; i++) {
         if (s.data[i] == u'\\')
@@ -304,3 +312,4 @@ String16 SkipWhitespace(String16 *string) {
     }
     return begin;
 }
+