diff -r 68ad5750ba6b -r 7960298039cf src/cx/allocator.h
--- a/src/cx/allocator.h	Sun Oct 03 10:43:31 2021 +0200
+++ b/src/cx/allocator.h	Sun Oct 03 12:02:57 2021 +0200
@@ -64,7 +64,8 @@
      * @param n the new size in bytes
      * @return a pointer to the re-allocated memory
      */
-    void *(*realloc)(void *data, void *mem, size_t n);
+    void *(*realloc)(void *data, void *mem, size_t n)
+    __attribute__((__warn_unused_result__));
 
     /**
      * Allocate \p nelem elements of \p n bytes each, all initialized to zero.
@@ -84,7 +85,8 @@
      * @param data the allocator's data
      * @param mem a pointer to the block to free
      */
-    void (*free)(void *data, void *mem);
+    void (*free)(void *data, void *mem)
+    __attribute__((__nonnull__));
 } cx_allocator_class;
 
 /**
@@ -118,8 +120,8 @@
  * @param n the number of bytes
  * @return a pointer to the allocated memory
  */
-__attribute__ ((malloc))
-void *cxMalloc(CxAllocator allocator, size_t n);
+void *cxMalloc(CxAllocator allocator, size_t n)
+__attribute__((__malloc__));
 
 /**
  * Re-allocate the previously allocated block in \p mem, making the new block \p n bytes long.
@@ -133,7 +135,8 @@
  * @param n the new size in bytes
  * @return a pointer to the re-allocated memory
  */
-void *cxRealloc(CxAllocator allocator, void *mem, size_t n);
+void *cxRealloc(CxAllocator allocator, void *mem, size_t n)
+__attribute__((warn_unused_result));
 
 /**
  * Re-allocate a previously allocated block and changes the pointer in-place, if necessary.
@@ -150,8 +153,8 @@
  * @param n the new size in bytes
  * @return zero on success, non-zero on failure
  */
-__attribute__ ((nonnull))
-int cxReallocate(CxAllocator allocator, void **mem, size_t n);
+int cxReallocate(CxAllocator allocator, void **mem, size_t n)
+__attribute__((nonnull));
 
 /**
  * Allocate \p nelem elements of \p n bytes each, all initialized to zero.
@@ -161,8 +164,8 @@
  * @param n the size of each element in bytes
  * @return a pointer to the allocated memory
  */
-__attribute__ ((malloc))
-void *cxCalloc(CxAllocator allocator, size_t nelem, size_t n);
+void *cxCalloc(CxAllocator allocator, size_t nelem, size_t n)
+__attribute__((malloc));
 
 /**
  * Free a block allocated by this allocator.
@@ -172,8 +175,8 @@
  * @param allocator the allocator
  * @param mem a pointer to the block to free
  */
-__attribute__((nonnull))
-void cxFree(CxAllocator allocator, void *mem);
+void cxFree(CxAllocator allocator, void *mem)
+__attribute__((nonnull));
 
 #ifdef __cplusplus
 } /* extern "C" */