Add str8_copy functions

tests/str8/test_str8.c

@@ -278,6 +278,41 @@ TestFuncResult test_str8_concat_capped(void) {
   return wapp_tester_result(result);
 }
 
+TestFuncResult test_str8_copy_cstr_capped(void) {
+  bool result;
+
+  Str8 buf         = wapp_str8_buf(32);
+  const char *src1 = "Hello world";
+  const char *src2 = "Hello world from the Wizard Apprentice standard library";
+  Str8RO src1_cp   = wapp_str8_lit_ro("Hello world");
+  Str8RO src2_cp   = wapp_str8_lit_ro("Hello world from the Wizard Appr");
+
+  wapp_str8_copy_cstr_capped(&buf, src1);
+  result = buf.size == src1_cp.size && wapp_str8_equal(&buf, &src1_cp);
+
+  wapp_str8_copy_cstr_capped(&buf, src2);
+  result = result && buf.size == src2_cp.size && buf.size == buf.capacity && wapp_str8_equal(&buf, &src2_cp);
+
+  return wapp_tester_result(result);
+}
+
+TestFuncResult test_str8_copy_str8_capped(void) {
+  bool result;
+
+  Str8 buf       = wapp_str8_buf(32);
+  Str8RO src1    = wapp_str8_lit_ro("Hello world");
+  Str8RO src2    = wapp_str8_lit_ro("Hello world from the Wizard Apprentice standard library");
+  Str8RO src2_cp = wapp_str8_lit_ro("Hello world from the Wizard Appr");
+
+  wapp_str8_copy_str8_capped(&buf, &src1);
+  result = buf.size == src1.size && wapp_str8_equal(&buf, &src1);
+
+  wapp_str8_copy_str8_capped(&buf, &src2);
+  result = result && buf.size < src2.size && buf.size == buf.capacity && wapp_str8_equal(&buf, &src2_cp);
+
+  return wapp_tester_result(result);
+}
+
 TestFuncResult test_str8_find(void) {
   bool result;
   Str8RO s = wapp_str8_lit("Do as I say, not as I do");

tests/str8/test_str8.h

@@ -20,6 +20,8 @@ TestFuncResult test_str8_equal(void);
 TestFuncResult test_str8_substr(void);
 TestFuncResult test_str8_concat(void);
 TestFuncResult test_str8_concat_capped(void);
+TestFuncResult test_str8_copy_cstr_capped(void);
+TestFuncResult test_str8_copy_str8_capped(void);
 TestFuncResult test_str8_find(void);
 TestFuncResult test_str8_rfind(void);
 TestFuncResult test_str8_split(void);