move xassert.h to assert/assert.h so it can be included as <assert.h> by prepending the assert/ dir to the include search path and use include_next to facilitate that. Removed -pedantic from C flags of examples because include_next is an extension.

CMakeLists.txt

@@ -4,10 +4,12 @@ project(xtest C)
 set(CMAKE_C_STANDARD 11)
 set(CMAKE_C_STANDARD_REQUIRED TRUE)
 
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wall -Werror -pedantic")
+set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wall -Werror")
 
 add_compile_definitions(XTEST)
 
+include_directories(BEFORE ${CMAKE_SOURCE_DIR}/assert)
+
 
 add_executable(example-all xtest.c examples/all.c examples/parameterized.c examples/assertions.c examples/expect_assertions.c examples/fail.c examples/groups.c examples/float.c examples/source.c examples/source.h examples/skip.c)
 target_compile_definitions(example-all PRIVATE XTEST_ALL_EXAMPLES)

assert/assert.h

@@ -1,12 +1,13 @@
+#if defined(__GNUC__) || defined(__clang__) || defined(XTEST_USE_INCLUDE_NEXT)
+#include_next <assert.h>
+#else
 #include <assert.h>
+#endif
 
 #define XTEST_XASSERT
 
-#if defined(XTEST_XTEST_H)  && !defined(XTEST_SOURCE)
-#error "do not include xtest.h and xassert.h at the same time. xassert.h should only be included from your source files and xtest.h should only be included from your test files."
-#endif
 
-#if defined(XTEST) && (!defined(XTEST_XTEST_H) || defined(XTEST_SOURCE))
+#if defined(XTEST) && !defined(XTEST_XTEST_H)
 
 void xtest_internal_assert(const char* file, int line, const char* func, const char* expr);
 

examples/source.c

@@ -1,6 +1,6 @@
 #include <string.h>
 #include "source.h"
-#include "../xassert.h"
+#include <assert.h>
 
 int ret_1() {
     return 1;

xtest.c

@@ -1,9 +1,6 @@
 #include <setjmp.h>
-
-#define XTEST_SOURCE
-
 #include "xtest.h"
-#include "xassert.h"
+#include <assert.h>
 
 struct xtest_assert_info {
     const char *file;

xtest.h

@@ -1,8 +1,8 @@
 #ifndef XTEST_XTEST_H
 #define XTEST_XTEST_H
 
-#if defined(XTEST_XASSERT) && !defined(XTEST_SOURCE)
-#error "do not include xtest.h and xassert.h at the same time. xassert.h should only be included from your source files and xtest.h should only be included from your test files."
+#if defined(XTEST_XASSERT)
+#error "do not include xtest.h before assert.h. If your tests make use of standard library assertions, include first xtest.h and then assert.h"
 #endif