provide a generic deconst_ptr function

This is generic enough to be used for various purposes. It will
only deconst their argument to work around various braindead
APIs without having to write a new wrapper each time we use one
of those braindead APIs.  It does not cast nor do do anything
other than quietly remove the const qualifier for those
braindead APIs.

1 files changed, 11 insertions, 0 deletions

diff --git a/src/utils.h b/src/utils.h
index 6a6e562cf..0001ba3c8 100644
--- a/src/utils.h
+++ b/src/utils.h
@@ -90,4 +90,15 @@ void xpthread_mutex_destroy(pthread_mutex_t *mutex);
 
 void xpthread_cond_destroy(pthread_cond_t *cond);
 
+/*
+ * Work-arounds for braindead APIs that require non-const pointers:
+ *   ao_play(), free(), vorbis_comment_add_tag(), iconv()
+ */
+static inline void * deconst_ptr(const void *ptr)
+{
+	union { const void *in; void *out; } u;
+	u.in = ptr;
+	return u.out;
+}
+
 #endif