Import official C23 code examples for Modern C (Jens Gustedt, 2024)HEADupstream-importmain

- Add official C source files, Makefile, c23-fallback.h, and LICENSE
- Update README.md with study mirror notice

1 files changed, 46 insertions, 0 deletions

diff --git a/test-lib.c b/test-lib.c
new file mode 100644
index 0000000..9430df0
--- /dev/null
+++ b/test-lib.c
@@ -0,0 +1,46 @@
+#include "c23-fallback.h"
+#include <stdio.h>
+
+typedef char const* key;
+
+
+int comp_key(key const*a, key const*b) {
+  key A = *a;
+  key B = *b;
+  return strcmp(A, B);
+}
+
+int comp(void const*a, void const*b) {
+  key const*A = a;
+  key const*B = b;
+  return comp_key(A, B);
+}
+
+int main() {
+  static key data[] = {
+    "Tina",
+    "Albert",
+    "Xaver",
+    "Albertina",
+  };
+
+  qsort(data, (sizeof data)/(sizeof data[0]), sizeof data[0], comp);
+  for (size_t i = 0; i < (sizeof data)/(sizeof data[0]); ++i)
+    printf("%zu: \"%s\"\n", i, data[i]);
+  key k = "Tina";
+  key* n1 = bsearch(&k, data, (sizeof data)/(sizeof data[0]), sizeof data[0], comp);
+  printf("found: \"%s\"\n", n1 ? *n1 : "unknown");
+  key const* d = data;
+  key const* n2 = bsearch(&k, d, (sizeof data)/(sizeof data[0]), sizeof data[0], comp);
+  printf("found: \"%s\"\n", n2 ? *n2 : "unknown");
+  char buf[25] = { 0 };
+  strfroml(buf, 25, "%.10g", 3744.0083383L);
+  printf("strfroml %.10LG → \"%s\"\n", 3744.0083383L, buf);
+  strfroml(buf, 25, "%.10Lg", 3744.0083383L);
+  printf("invalid format leads to \"%s\"\n", buf);
+  for (char const* p = buf; p < buf+16; ++p)
+    printf("alignment %p: %zu, suitable for int*: %d\n", p, memalignment(p), memalignment(p)>=alignof(int));
+  struct two {int a; int b; };
+  assert((struct two){ .a = 0, .b = 1, }.b);
+  assert((struct two){ .a = 0, .b = 1, }.a);
+}