diff -r 6456036bbb37 -r edb9f875b7f9 src/cx/printf.h
--- a/src/cx/printf.h	Wed Apr 03 21:22:23 2024 +0200
+++ b/src/cx/printf.h	Fri Apr 12 21:48:12 2024 +0200
@@ -168,12 +168,12 @@
 /**
  * An \c sprintf like function which reallocates the string when the buffer is not large enough.
  *
+ * The size of the buffer will be updated in \p len when necessary.
+ *
  * \note The resulting string is guaranteed to be zero-terminated.
- * That means, when the buffer needed to be reallocated, the new size of the buffer will be
- * the length returned by this function plus one.
  *
  * @param str a pointer to the string buffer
- * @param len the current length of the buffer
+ * @param len a pointer to the length of the buffer
  * @param fmt the format string
  * @param ... additional arguments
  * @return the length of produced string
@@ -183,32 +183,32 @@
 /**
  * An \c sprintf like function which reallocates the string when the buffer is not large enough.
  *
+ * The size of the buffer will be updated in \p len when necessary.
+ *
  * \note The resulting string is guaranteed to be zero-terminated.
- * That means, when the buffer needed to be reallocated, the new size of the buffer will be
- * the length returned by this function plus one.
  *
  * \attention The original buffer MUST have been allocated with the same allocator!
  *
  * @param alloc the allocator to use
  * @param str a pointer to the string buffer
- * @param len the current length of the buffer
+ * @param len a pointer to the length of the buffer
  * @param fmt the format string
  * @param ... additional arguments
  * @return the length of produced string
  */
-__attribute__((__nonnull__(1, 2, 4), __format__(printf, 4, 5)))
-int cx_sprintf_a(CxAllocator *alloc, char **str, size_t len, const char *fmt, ... );
+__attribute__((__nonnull__(1, 2, 3, 4), __format__(printf, 4, 5)))
+int cx_sprintf_a(CxAllocator *alloc, char **str, size_t *len, const char *fmt, ... );
 
 
 /**
  * An \c sprintf like function which reallocates the string when the buffer is not large enough.
  *
+ * The size of the buffer will be updated in \p len when necessary.
+ *
  * \note The resulting string is guaranteed to be zero-terminated.
- * That means, when the buffer needed to be reallocated, the new size of the buffer will be
- * the length returned by this function plus one.
  *
  * @param str a pointer to the string buffer
- * @param len the current length of the buffer
+ * @param len a pointer to the length of the buffer
  * @param fmt the format string
  * @param ap argument list
  * @return the length of produced string
@@ -218,38 +218,38 @@
 /**
  * An \c sprintf like function which reallocates the string when the buffer is not large enough.
  *
+ * The size of the buffer will be updated in \p len when necessary.
+ *
  * \note The resulting string is guaranteed to be zero-terminated.
- * That means, when the buffer needed to be reallocated, the new size of the buffer will be
- * the length returned by this function plus one.
  *
  * \attention The original buffer MUST have been allocated with the same allocator!
  *
  * @param alloc the allocator to use
  * @param str a pointer to the string buffer
- * @param len the current length of the buffer
+ * @param len a pointer to the length of the buffer
  * @param fmt the format string
  * @param ap argument list
  * @return the length of produced string
  */
 __attribute__((__nonnull__))
-int cx_vsprintf_a(CxAllocator *alloc, char **str, size_t len, const char *fmt, va_list ap);
+int cx_vsprintf_a(CxAllocator *alloc, char **str, size_t *len, const char *fmt, va_list ap);
 
 
 /**
  * An \c sprintf like function which allocates a new string when the buffer is not large enough.
  *
+ * The size of the buffer will be updated in \p len when necessary.
+ *
  * The location of the resulting string will \em always be stored to \p str. When the buffer
  * was sufficiently large, \p buf itself will be stored to the location of \p str.
  *
  * \note The resulting string is guaranteed to be zero-terminated.
- * That means, when the buffer needed to be reallocated, the new size of the buffer will be
- * the length returned by this function plus one.
  * 
  * \remark When a new string needed to be allocated, the contents of \p buf will be
  * poisoned after the call, because this function tries to produce the string in \p buf, first.
  *
  * @param buf a pointer to the buffer
- * @param len the length of the buffer
+ * @param len a pointer to the length of the buffer
  * @param str a pointer to the location
  * @param fmt the format string
  * @param ... additional arguments
@@ -260,42 +260,42 @@
 /**
  * An \c sprintf like function which allocates a new string when the buffer is not large enough.
  *
+ * The size of the buffer will be updated in \p len when necessary.
+ *
  * The location of the resulting string will \em always be stored to \p str. When the buffer
  * was sufficiently large, \p buf itself will be stored to the location of \p str.
  *
  * \note The resulting string is guaranteed to be zero-terminated.
- * That means, when the buffer needed to be reallocated, the new size of the buffer will be
- * the length returned by this function plus one.
  *
  * \remark When a new string needed to be allocated, the contents of \p buf will be
  * poisoned after the call, because this function tries to produce the string in \p buf, first.
  *
  * @param alloc the allocator to use
  * @param buf a pointer to the buffer
- * @param len the length of the buffer
+ * @param len a pointer to the length of the buffer
  * @param str a pointer to the location
  * @param fmt the format string
  * @param ... additional arguments
  * @return the length of produced string
  */
 __attribute__((__nonnull__(1, 2, 4, 5), __format__(printf, 5, 6)))
-int cx_sprintf_sa(CxAllocator *alloc, char *buf, size_t len, char **str, const char *fmt, ... );
+int cx_sprintf_sa(CxAllocator *alloc, char *buf, size_t *len, char **str, const char *fmt, ... );
 
 /**
  * An \c sprintf like function which allocates a new string when the buffer is not large enough.
  *
+ * The size of the buffer will be updated in \p len when necessary.
+ *
  * The location of the resulting string will \em always be stored to \p str. When the buffer
  * was sufficiently large, \p buf itself will be stored to the location of \p str.
  *
  * \note The resulting string is guaranteed to be zero-terminated.
- * That means, when the buffer needed to be reallocated, the new size of the buffer will be
- * the length returned by this function plus one.
  *
  * \remark When a new string needed to be allocated, the contents of \p buf will be
  * poisoned after the call, because this function tries to produce the string in \p buf, first.
  *
  * @param buf a pointer to the buffer
- * @param len the length of the buffer
+ * @param len a pointer to the length of the buffer
  * @param str a pointer to the location
  * @param fmt the format string
  * @param ap argument list
@@ -306,26 +306,26 @@
 /**
  * An \c sprintf like function which allocates a new string when the buffer is not large enough.
  *
+ * The size of the buffer will be updated in \p len when necessary.
+ *
  * The location of the resulting string will \em always be stored to \p str. When the buffer
  * was sufficiently large, \p buf itself will be stored to the location of \p str.
  *
  * \note The resulting string is guaranteed to be zero-terminated.
- * That means, when the buffer needed to be reallocated, the new size of the buffer will be
- * the length returned by this function plus one.
  *
  * \remark When a new string needed to be allocated, the contents of \p buf will be
  * poisoned after the call, because this function tries to produce the string in \p buf, first.
  *
  * @param alloc the allocator to use
  * @param buf a pointer to the buffer
- * @param len the length of the buffer
+ * @param len a pointer to the length of the buffer
  * @param str a pointer to the location
  * @param fmt the format string
  * @param ap argument list
  * @return the length of produced string
  */
 __attribute__((__nonnull__))
-int cx_vsprintf_sa(CxAllocator *alloc, char *buf, size_t len, char **str, const char *fmt, va_list ap);
+int cx_vsprintf_sa(CxAllocator *alloc, char *buf, size_t *len, char **str, const char *fmt, va_list ap);
 
 
 #ifdef __cplusplus