include more of Boolean.h

git-svn-id: https://svn.r-project.org/R/trunk@87949 00db46b3-68df-0310-9c12-caf00c1e9a41

Author: ripley

src/include/Rmath.h0.in

@@ -196,6 +196,14 @@ double  Rlog1p(double);
  #undef FALSE
  #undef TRUE
  typedef enum { FALSE = 0, TRUE } Rboolean;
+ // stdbool.h is obsolescent but we could pro tem just use it.
+ // But to future-proof copy from Boolean.h
+ #if defined __STDC_VERSION__ && __STDC_VERSION__ > 202000L
+ #elif defined __cplusplus
+ #else
+  # include <stdbool.h>
+ #endif
+
 # endif
 #else
 # include <R_ext/Boolean.h>