add metalang99 testsuite (preprocessor stress testing)

1 files changed, 31 insertions, 0 deletions

diff --git a/test/external/metalang99/examples/assert_for_each.c b/test/external/metalang99/examples/assert_for_each.c
new file mode 100644
index 0000000..3ba9127
--- /dev/null
+++ b/test/external/metalang99/examples/assert_for_each.c
@@ -0,0 +1,31 @@
+// Asserts multiple expressions at once.
+
+#include <metalang99.h>
+
+#include <assert.h>
+
+#define ASSERT_FOR_EACH(...)                                                                       \
+    do {                                                                                           \
+        ML99_EVAL(ML99_variadicsForEach(                                                           \
+            ML99_compose(v(ML99_semicoloned), ML99_reify(v(assert))),                              \
+            v(__VA_ARGS__)))                                                                       \
+    } while (0)
+
+int main(void) {
+    ASSERT_FOR_EACH(123 == 123, 2 + 2 == 4, "foo"[1] == 'o');
+
+    /*
+     * If we combine multiple assertions with the && operator, we will not be able to distinguish
+     * them if one of them fails apparently:
+     *
+     * main: Assertion `123 == 321 && 2 + 2 == 4 && "foo"[1] == 'o' failed.
+     * assert(123 == 321 && 2 + 2 == 4 && "foo"[1] == 'o');
+     */
+
+    /*
+     * ... unlike `ASSERT_FOR_EACH` telling us which one has failed:
+     *
+     * main: Assertion `123 == 321' failed.
+     * ASSERT_FOR_EACH(123 == 321, 2 + 2 == 4, "foo"[1] == 'o');
+     */
+}