MINOR: ist: Add `istappend(struct ist, char)`
This function appends the given char to the given `ist` and returns
the resulting `ist`.
diff --git a/include/import/ist.h b/include/import/ist.h
index 1262e8f..3f63ed2 100644
--- a/include/import/ist.h
+++ b/include/import/ist.h
@@ -407,6 +407,16 @@
return isteq(l, r);
}
+/* appends <src> after <dst>. The caller must ensure that the underlying buffer
+ * is large enough to fit the character.
+ */
+static inline struct ist istappend(struct ist dst, const char src)
+{
+ dst.ptr[dst.len++] = src;
+
+ return dst;
+}
+
/* copies <src> over <dst> for a maximum of <count> bytes. Returns the number
* of characters copied (src.len), or -1 if it does not fit. In all cases, the
* contents are copied prior to reporting an error, so that the destination