+#ifndef __cplusplus
+#define __CIMAG(x, t) \
+ (+(union { _Complex t __z; t __xy[2]; }){(_Complex t)(x)}.__xy[1])
+
+#define creal(x) ((double)(x))
+#define crealf(x) ((float)(x))
+#define creall(x) ((long double)(x))
+
+#define cimag(x) __CIMAG(x, double)
+#define cimagf(x) __CIMAG(x, float)
+#define cimagl(x) __CIMAG(x, long double)
+#endif
+
+#if __STDC_VERSION__ >= 201112L
+#if defined(_Imaginary_I)
+#define __CMPLX(x, y, t) ((t)(x) + _Imaginary_I*(t)(y))
+#elif defined(__clang__)
+#define __CMPLX(x, y, t) (+(_Complex t){ (t)(x), (t)(y) })
+#else
+#define __CMPLX(x, y, t) (__builtin_complex((t)(x), (t)(y)))
+#endif
+#define CMPLX(x, y) __CMPLX(x, y, double)
+#define CMPLXF(x, y) __CMPLX(x, y, float)
+#define CMPLXL(x, y) __CMPLX(x, y, long double)
+#endif
+