X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=lib%2Fmath.in.h;h=721ddf500dfb356cd39bcdb7797c24a19b538982;hb=579928caf1c6bb983cbba7ee18603c077be78392;hp=a63765824256a21f782fa44d275cdb52acb0a4a3;hpb=21492d6c3ca00ff0827528640804732f2ed66470;p=gnulib.git

diff --git a/lib/math.in.h b/lib/math.in.h
index a63765824..721ddf500 100644
--- a/lib/math.in.h
+++ b/lib/math.in.h
@@ -1,6 +1,6 @@
 /* A GNU-like <math.h>.
 
-   Copyright (C) 2002-2003, 2007-2011 Free Software Foundation, Inc.
+   Copyright (C) 2002-2003, 2007-2012 Free Software Foundation, Inc.
 
    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -35,6 +35,44 @@
 
 /* The definition of _GL_WARN_ON_USE is copied here.  */
 
+#ifdef __cplusplus
+/* Helper macros to define type-generic function FUNC as overloaded functions,
+   rather than as macros like in C.  POSIX declares these with an argument of
+   real-floating (that is, one of float, double, or long double).  */
+# define _GL_MATH_CXX_REAL_FLOATING_DECL_1(func) \
+static inline int                                                   \
+_gl_cxx_ ## func ## f (float f)                                     \
+{                                                                   \
+  return func (f);                                                  \
+}                                                                   \
+static inline int                                                   \
+_gl_cxx_ ## func ## d (double d)                                    \
+{                                                                   \
+  return func (d);                                                  \
+}                                                                   \
+static inline int                                                   \
+_gl_cxx_ ## func ## l (long double l)                               \
+{                                                                   \
+  return func (l);                                                  \
+}
+# define _GL_MATH_CXX_REAL_FLOATING_DECL_2(func) \
+inline int                                                          \
+func (float f)                                                      \
+{                                                                   \
+  return _gl_cxx_ ## func ## f (f);                                 \
+}                                                                   \
+inline int                                                          \
+func (double d)                                                     \
+{                                                                   \
+  return _gl_cxx_ ## func ## d (d);                                 \
+}                                                                   \
+inline int                                                          \
+func (long double l)                                                \
+{                                                                   \
+  return _gl_cxx_ ## func ## l (l);                                 \
+}
+#endif
+
 /* Helper macros to define a portability warning for the
    classification macro FUNC called with VALUE.  POSIX declares the
    classification macros with an argument of real-floating (that is,
@@ -125,6 +163,7 @@ _GL_WARN_ON_USE (acosf, "acosf is unportable - "
 
 #if @GNULIB_ACOSL@
 # if !@HAVE_ACOSL@ || !@HAVE_DECL_ACOSL@
+#  undef acosl
 _GL_FUNCDECL_SYS (acosl, long double, (long double x));
 # endif
 _GL_CXXALIAS_SYS (acosl, long double, (long double x));
@@ -155,6 +194,7 @@ _GL_WARN_ON_USE (asinf, "asinf is unportable - "
 
 #if @GNULIB_ASINL@
 # if !@HAVE_ASINL@ || !@HAVE_DECL_ASINL@
+#  undef asinl
 _GL_FUNCDECL_SYS (asinl, long double, (long double x));
 # endif
 _GL_CXXALIAS_SYS (asinl, long double, (long double x));
@@ -185,6 +225,7 @@ _GL_WARN_ON_USE (atanf, "atanf is unportable - "
 
 #if @GNULIB_ATANL@
 # if !@HAVE_ATANL@ || !@HAVE_DECL_ATANL@
+#  undef atanl
 _GL_FUNCDECL_SYS (atanl, long double, (long double x));
 # endif
 _GL_CXXALIAS_SYS (atanl, long double, (long double x));
@@ -224,6 +265,7 @@ _GL_FUNCDECL_RPL (ceilf, float, (float x));
 _GL_CXXALIAS_RPL (ceilf, float, (float x));
 # else
 #  if !@HAVE_DECL_CEILF@
+#   undef ceilf
 _GL_FUNCDECL_SYS (ceilf, float, (float x));
 #  endif
 _GL_CXXALIAS_SYS (ceilf, float, (float x));
@@ -260,6 +302,7 @@ _GL_FUNCDECL_RPL (ceill, long double, (long double x));
 _GL_CXXALIAS_RPL (ceill, long double, (long double x));
 # else
 #  if !@HAVE_DECL_CEILL@
+#   undef ceill
 _GL_FUNCDECL_SYS (ceill, long double, (long double x));
 #  endif
 _GL_CXXALIAS_SYS (ceill, long double, (long double x));
@@ -274,6 +317,49 @@ _GL_WARN_ON_USE (ceill, "ceill is unportable - "
 #endif
 
 
+#if @GNULIB_COPYSIGNF@
+# if !@HAVE_COPYSIGNF@
+_GL_FUNCDECL_SYS (copysignf, float, (float x, float y));
+# endif
+_GL_CXXALIAS_SYS (copysignf, float, (float x, float y));
+_GL_CXXALIASWARN (copysignf);
+#elif defined GNULIB_POSIXCHECK
+# undef copysignf
+# if HAVE_RAW_DECL_COPYSIGNF
+_GL_WARN_ON_USE (copysignf, "copysignf is unportable - "
+                 "use gnulib module copysignf for portability");
+# endif
+#endif
+
+#if @GNULIB_COPYSIGN@
+# if !@HAVE_COPYSIGN@
+_GL_FUNCDECL_SYS (copysign, double, (double x, double y));
+# endif
+_GL_CXXALIAS_SYS (copysign, double, (double x, double y));
+_GL_CXXALIASWARN (copysign);
+#elif defined GNULIB_POSIXCHECK
+# undef copysign
+# if HAVE_RAW_DECL_COPYSIGN
+_GL_WARN_ON_USE (copysign, "copysign is unportable - "
+                 "use gnulib module copysign for portability");
+# endif
+#endif
+
+#if @GNULIB_COPYSIGNL@
+# if !@HAVE_COPYSIGNL@
+_GL_FUNCDECL_SYS (copysignl, long double, (long double x, long double y));
+# endif
+_GL_CXXALIAS_SYS (copysignl, long double, (long double x, long double y));
+_GL_CXXALIASWARN (copysignl);
+#elif defined GNULIB_POSIXCHECK
+# undef copysignl
+# if HAVE_RAW_DECL_COPYSIGNL
+_GL_WARN_ON_USE (copysign, "copysignl is unportable - "
+                 "use gnulib module copysignl for portability");
+# endif
+#endif
+
+
 #if @GNULIB_COSF@
 # if !@HAVE_COSF@
 #  undef cosf
@@ -291,6 +377,7 @@ _GL_WARN_ON_USE (cosf, "cosf is unportable - "
 
 #if @GNULIB_COSL@
 # if !@HAVE_COSL@ || !@HAVE_DECL_COSL@
+#  undef cosl
 _GL_FUNCDECL_SYS (cosl, long double, (long double x));
 # endif
 _GL_CXXALIAS_SYS (cosl, long double, (long double x));
@@ -337,6 +424,7 @@ _GL_WARN_ON_USE (expf, "expf is unportable - "
 
 #if @GNULIB_EXPL@
 # if !@HAVE_EXPL@ || !@HAVE_DECL_EXPL@
+#  undef expl
 _GL_FUNCDECL_SYS (expl, long double, (long double x));
 # endif
 _GL_CXXALIAS_SYS (expl, long double, (long double x));
@@ -365,6 +453,30 @@ _GL_WARN_ON_USE (fabsf, "fabsf is unportable - "
 # endif
 #endif
 
+#if @GNULIB_FABSL@
+# if @REPLACE_FABSL@
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   undef fabsl
+#   define fabsl rpl_fabsl
+#  endif
+_GL_FUNCDECL_RPL (fabsl, long double, (long double x));
+_GL_CXXALIAS_RPL (fabsl, long double, (long double x));
+# else
+#  if !@HAVE_FABSL@
+#   undef fabsl
+_GL_FUNCDECL_SYS (fabsl, long double, (long double x));
+#  endif
+_GL_CXXALIAS_SYS (fabsl, long double, (long double x));
+# endif
+_GL_CXXALIASWARN (fabsl);
+#elif defined GNULIB_POSIXCHECK
+# undef fabsl
+# if HAVE_RAW_DECL_FABSL
+_GL_WARN_ON_USE (fabsl, "fabsl is unportable - "
+                 "use gnulib module fabsl for portability");
+# endif
+#endif
+
 
 #if @GNULIB_FLOORF@
 # if @REPLACE_FLOORF@
@@ -376,6 +488,7 @@ _GL_FUNCDECL_RPL (floorf, float, (float x));
 _GL_CXXALIAS_RPL (floorf, float, (float x));
 # else
 #  if !@HAVE_DECL_FLOORF@
+#   undef floorf
 _GL_FUNCDECL_SYS (floorf, float, (float x));
 #  endif
 _GL_CXXALIAS_SYS (floorf, float, (float x));
@@ -412,6 +525,7 @@ _GL_FUNCDECL_RPL (floorl, long double, (long double x));
 _GL_CXXALIAS_RPL (floorl, long double, (long double x));
 # else
 #  if !@HAVE_DECL_FLOORL@
+#   undef floorl
 _GL_FUNCDECL_SYS (floorl, long double, (long double x));
 #  endif
 _GL_CXXALIAS_SYS (floorl, long double, (long double x));
@@ -426,6 +540,80 @@ _GL_WARN_ON_USE (floorl, "floorl is unportable - "
 #endif
 
 
+#if @GNULIB_FMAF@
+# if @REPLACE_FMAF@
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   undef fmaf
+#   define fmaf rpl_fmaf
+#  endif
+_GL_FUNCDECL_RPL (fmaf, float, (float x, float y, float z));
+_GL_CXXALIAS_RPL (fmaf, float, (float x, float y, float z));
+# else
+#  if !@HAVE_FMAF@
+_GL_FUNCDECL_SYS (fmaf, float, (float x, float y, float z));
+#  endif
+_GL_CXXALIAS_SYS (fmaf, float, (float x, float y, float z));
+# endif
+_GL_CXXALIASWARN (fmaf);
+#elif defined GNULIB_POSIXCHECK
+# undef fmaf
+# if HAVE_RAW_DECL_FMAF
+_GL_WARN_ON_USE (fmaf, "fmaf is unportable - "
+                 "use gnulib module fmaf for portability");
+# endif
+#endif
+
+#if @GNULIB_FMA@
+# if @REPLACE_FMA@
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   undef fma
+#   define fma rpl_fma
+#  endif
+_GL_FUNCDECL_RPL (fma, double, (double x, double y, double z));
+_GL_CXXALIAS_RPL (fma, double, (double x, double y, double z));
+# else
+#  if !@HAVE_FMA@
+_GL_FUNCDECL_SYS (fma, double, (double x, double y, double z));
+#  endif
+_GL_CXXALIAS_SYS (fma, double, (double x, double y, double z));
+# endif
+_GL_CXXALIASWARN (fma);
+#elif defined GNULIB_POSIXCHECK
+# undef fma
+# if HAVE_RAW_DECL_FMA
+_GL_WARN_ON_USE (fma, "fma is unportable - "
+                 "use gnulib module fma for portability");
+# endif
+#endif
+
+#if @GNULIB_FMAL@
+# if @REPLACE_FMAL@
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   undef fmal
+#   define fmal rpl_fmal
+#  endif
+_GL_FUNCDECL_RPL (fmal, long double,
+                  (long double x, long double y, long double z));
+_GL_CXXALIAS_RPL (fmal, long double,
+                  (long double x, long double y, long double z));
+# else
+#  if !@HAVE_FMAL@
+_GL_FUNCDECL_SYS (fmal, long double,
+                  (long double x, long double y, long double z));
+#  endif
+_GL_CXXALIAS_SYS (fmal, long double,
+                  (long double x, long double y, long double z));
+# endif
+_GL_CXXALIASWARN (fmal);
+#elif defined GNULIB_POSIXCHECK
+# undef fmal
+# if HAVE_RAW_DECL_FMAL
+_GL_WARN_ON_USE (fmal, "fmal is unportable - "
+                 "use gnulib module fmal for portability");
+# endif
+#endif
+
+
 #if @GNULIB_FMODF@
 # if !@HAVE_FMODF@
 #  undef fmodf
@@ -441,6 +629,30 @@ _GL_WARN_ON_USE (fmodf, "fmodf is unportable - "
 # endif
 #endif
 
+#if @GNULIB_FMODL@
+# if @REPLACE_FMODL@
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   undef fmodl
+#   define fmodl rpl_fmodl
+#  endif
+_GL_FUNCDECL_RPL (fmodl, long double, (long double x, long double y));
+_GL_CXXALIAS_RPL (fmodl, long double, (long double x, long double y));
+# else
+#  if !@HAVE_FMODL@
+#   undef fmodl
+_GL_FUNCDECL_SYS (fmodl, long double, (long double x, long double y));
+#  endif
+_GL_CXXALIAS_SYS (fmodl, long double, (long double x, long double y));
+# endif
+_GL_CXXALIASWARN (fmodl);
+#elif defined GNULIB_POSIXCHECK
+# undef fmodl
+# if HAVE_RAW_DECL_FMODL
+_GL_WARN_ON_USE (fmodl, "fmodl is unportable - "
+                 "use gnulib module fmodl for portability");
+# endif
+#endif
+
 
 /* Write x as
      x = mantissa * 2^exp
@@ -608,6 +820,7 @@ _GL_WARN_ON_USE (logf, "logf is unportable - "
 
 #if @GNULIB_LOGL@
 # if !@HAVE_LOGL@ || !@HAVE_DECL_LOGL@
+#  undef logl
 _GL_FUNCDECL_SYS (logl, long double, (long double x));
 # endif
 _GL_CXXALIAS_SYS (logl, long double, (long double x));
@@ -636,13 +849,37 @@ _GL_WARN_ON_USE (log10f, "log10f is unportable - "
 # endif
 #endif
 
+#if @GNULIB_LOG10L@
+# if !@HAVE_LOG10L@ || !@HAVE_DECL_LOG10L@
+#  undef log10l
+_GL_FUNCDECL_SYS (log10l, long double, (long double x));
+# endif
+_GL_CXXALIAS_SYS (log10l, long double, (long double x));
+_GL_CXXALIASWARN (log10l);
+#elif defined GNULIB_POSIXCHECK
+# undef log10l
+# if HAVE_RAW_DECL_LOG10L
+_GL_WARN_ON_USE (log10l, "log10l is unportable - "
+                 "use gnulib module log10l for portability");
+# endif
+#endif
+
 
 #if @GNULIB_MODFF@
-# if !@HAVE_MODFF@
-#  undef modff
+# if @REPLACE_MODFF@
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   undef modff
+#   define modff rpl_modff
+#  endif
+_GL_FUNCDECL_RPL (modff, float, (float x, float *iptr) _GL_ARG_NONNULL ((2)));
+_GL_CXXALIAS_RPL (modff, float, (float x, float *iptr));
+# else
+#  if !@HAVE_MODFF@
+#   undef modff
 _GL_FUNCDECL_SYS (modff, float, (float x, float *iptr) _GL_ARG_NONNULL ((2)));
-# endif
+#  endif
 _GL_CXXALIAS_SYS (modff, float, (float x, float *iptr));
+# endif
 _GL_CXXALIASWARN (modff);
 #elif defined GNULIB_POSIXCHECK
 # undef modff
@@ -652,6 +889,52 @@ _GL_WARN_ON_USE (modff, "modff is unportable - "
 # endif
 #endif
 
+#if @GNULIB_MODF@
+# if @REPLACE_MODF@
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   undef modf
+#   define modf rpl_modf
+#  endif
+_GL_FUNCDECL_RPL (modf, double, (double x, double *iptr) _GL_ARG_NONNULL ((2)));
+_GL_CXXALIAS_RPL (modf, double, (double x, double *iptr));
+# else
+_GL_CXXALIAS_SYS (modf, double, (double x, double *iptr));
+# endif
+_GL_CXXALIASWARN (modf);
+#elif defined GNULIB_POSIXCHECK
+# undef modf
+# if HAVE_RAW_DECL_MODF
+_GL_WARN_ON_USE (modf, "modf has portability problems - "
+                 "use gnulib module modf for portability");
+# endif
+#endif
+
+#if @GNULIB_MODFL@
+# if @REPLACE_MODFL@
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   undef modfl
+#   define modfl rpl_modfl
+#  endif
+_GL_FUNCDECL_RPL (modfl, long double, (long double x, long double *iptr)
+                                      _GL_ARG_NONNULL ((2)));
+_GL_CXXALIAS_RPL (modfl, long double, (long double x, long double *iptr));
+# else
+#  if !@HAVE_MODFL@
+#   undef modfl
+_GL_FUNCDECL_SYS (modfl, long double, (long double x, long double *iptr)
+                                      _GL_ARG_NONNULL ((2)));
+#  endif
+_GL_CXXALIAS_SYS (modfl, long double, (long double x, long double *iptr));
+# endif
+_GL_CXXALIASWARN (modfl);
+#elif defined GNULIB_POSIXCHECK
+# undef modfl
+# if HAVE_RAW_DECL_MODFL
+_GL_WARN_ON_USE (modfl, "modfl is unportable - "
+                 "use gnulib module modfl for portability");
+# endif
+#endif
+
 
 #if @GNULIB_POWF@
 # if !@HAVE_POWF@
@@ -669,6 +952,92 @@ _GL_WARN_ON_USE (powf, "powf is unportable - "
 #endif
 
 
+#if @GNULIB_REMAINDERF@
+# if !@HAVE_REMAINDERF@
+_GL_FUNCDECL_SYS (remainderf, float, (float x, float y));
+# endif
+_GL_CXXALIAS_SYS (remainderf, float, (float x, float y));
+_GL_CXXALIASWARN (remainderf);
+#elif defined GNULIB_POSIXCHECK
+# undef remainderf
+# if HAVE_RAW_DECL_REMAINDERF
+_GL_WARN_ON_USE (remainderf, "remainderf is unportable - "
+                 "use gnulib module remainderf for portability");
+# endif
+#endif
+
+#if @GNULIB_REMAINDER@
+# if !@HAVE_REMAINDER@ || !@HAVE_DECL_REMAINDER@
+_GL_FUNCDECL_SYS (remainder, double, (double x, double y));
+# endif
+_GL_CXXALIAS_SYS (remainder, double, (double x, double y));
+_GL_CXXALIASWARN (remainder);
+#elif defined GNULIB_POSIXCHECK
+# undef remainder
+# if HAVE_RAW_DECL_REMAINDER
+_GL_WARN_ON_USE (remainder, "remainder is unportable - "
+                 "use gnulib module remainder for portability");
+# endif
+#endif
+
+#if @GNULIB_REMAINDERL@
+# if !@HAVE_REMAINDERL@
+_GL_FUNCDECL_SYS (remainderl, long double, (long double x, long double y));
+# endif
+_GL_CXXALIAS_SYS (remainderl, long double, (long double x, long double y));
+_GL_CXXALIASWARN (remainderl);
+#elif defined GNULIB_POSIXCHECK
+# undef remainderl
+# if HAVE_RAW_DECL_REMAINDERL
+_GL_WARN_ON_USE (remainderl, "remainderl is unportable - "
+                 "use gnulib module remainderl for portability");
+# endif
+#endif
+
+
+#if @GNULIB_RINTF@
+# if !@HAVE_RINTF@
+_GL_FUNCDECL_SYS (rintf, float, (float x));
+# endif
+_GL_CXXALIAS_SYS (rintf, float, (float x));
+_GL_CXXALIASWARN (rintf);
+#elif defined GNULIB_POSIXCHECK
+# undef rintf
+# if HAVE_RAW_DECL_RINTF
+_GL_WARN_ON_USE (rintf, "rintf is unportable - "
+                 "use gnulib module rintf for portability");
+# endif
+#endif
+
+#if @GNULIB_RINT@
+# if !@HAVE_RINT@
+_GL_FUNCDECL_SYS (rint, double, (double x));
+# endif
+_GL_CXXALIAS_SYS (rint, double, (double x));
+_GL_CXXALIASWARN (rint);
+#elif defined GNULIB_POSIXCHECK
+# undef rint
+# if HAVE_RAW_DECL_RINT
+_GL_WARN_ON_USE (rint, "rint is unportable - "
+                 "use gnulib module rint for portability");
+# endif
+#endif
+
+#if @GNULIB_RINTL@
+# if !@HAVE_RINTL@
+_GL_FUNCDECL_SYS (rintl, long double, (long double x));
+# endif
+_GL_CXXALIAS_SYS (rintl, long double, (long double x));
+_GL_CXXALIASWARN (rintl);
+#elif defined GNULIB_POSIXCHECK
+# undef rintl
+# if HAVE_RAW_DECL_RINTL
+_GL_WARN_ON_USE (rintl, "rintl is unportable - "
+                 "use gnulib module rintl for portability");
+# endif
+#endif
+
+
 #if @GNULIB_ROUNDF@
 # if @REPLACE_ROUNDF@
 #  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
@@ -756,6 +1125,7 @@ _GL_WARN_ON_USE (sinf, "sinf is unportable - "
 
 #if @GNULIB_SINL@
 # if !@HAVE_SINL@ || !@HAVE_DECL_SINL@
+#  undef sinl
 _GL_FUNCDECL_SYS (sinl, long double, (long double x));
 # endif
 _GL_CXXALIAS_SYS (sinl, long double, (long double x));
@@ -802,6 +1172,7 @@ _GL_WARN_ON_USE (sqrtf, "sqrtf is unportable - "
 
 #if @GNULIB_SQRTL@
 # if !@HAVE_SQRTL@ || !@HAVE_DECL_SQRTL@
+#  undef sqrtl
 _GL_FUNCDECL_SYS (sqrtl, long double, (long double x));
 # endif
 _GL_CXXALIAS_SYS (sqrtl, long double, (long double x));
@@ -832,6 +1203,7 @@ _GL_WARN_ON_USE (tanf, "tanf is unportable - "
 
 #if @GNULIB_TANL@
 # if !@HAVE_TANL@ || !@HAVE_DECL_TANL@
+#  undef tanl
 _GL_FUNCDECL_SYS (tanl, long double, (long double x));
 # endif
 _GL_CXXALIAS_SYS (tanl, long double, (long double x));
@@ -944,6 +1316,13 @@ _GL_EXTERN_C int gl_isfinitel (long double x);
     sizeof (x) == sizeof (double) ? gl_isfinited (x) : \
     gl_isfinitef (x))
 # endif
+# ifdef __cplusplus
+#  ifdef isfinite
+_GL_MATH_CXX_REAL_FLOATING_DECL_1 (isfinite)
+#   undef isfinite
+_GL_MATH_CXX_REAL_FLOATING_DECL_2 (isfinite)
+#  endif
+# endif
 #elif defined GNULIB_POSIXCHECK
 # if defined isfinite
 _GL_WARN_REAL_FLOATING_DECL (isfinite);
@@ -964,6 +1343,13 @@ _GL_EXTERN_C int gl_isinfl (long double x);
     sizeof (x) == sizeof (double) ? gl_isinfd (x) : \
     gl_isinff (x))
 # endif
+# ifdef __cplusplus
+#  ifdef isinf
+_GL_MATH_CXX_REAL_FLOATING_DECL_1 (isinf)
+#   undef isinf
+_GL_MATH_CXX_REAL_FLOATING_DECL_2 (isinf)
+#  endif
+# endif
 #elif defined GNULIB_POSIXCHECK
 # if defined isinf
 _GL_WARN_REAL_FLOATING_DECL (isinf);
@@ -1034,7 +1420,7 @@ _GL_EXTERN_C int isnand (double x);
 /* Test whether X is a NaN.  */
 #  undef isnanl
 #  define isnanl rpl_isnanl
-_GL_EXTERN_C int isnanl (long double x);
+_GL_EXTERN_C int isnanl (long double x) _GL_ATTRIBUTE_CONST;
 # endif
 #endif
 
@@ -1060,7 +1446,7 @@ _GL_EXTERN_C int rpl_isnand (double x);
 #  if @HAVE_ISNANL@ && __GNUC__ >= 4
 #   define gl_isnan_l(x) __builtin_isnanl ((long double)(x))
 #  else
-_GL_EXTERN_C int rpl_isnanl (long double x);
+_GL_EXTERN_C int rpl_isnanl (long double x) _GL_ATTRIBUTE_CONST;
 #   define gl_isnan_l(x) rpl_isnanl (x)
 #  endif
 #  undef isnan
@@ -1075,9 +1461,17 @@ _GL_EXTERN_C int rpl_isnanl (long double x);
     sizeof (x) == sizeof (double) ? __builtin_isnan ((double)(x)) : \
     __builtin_isnanf ((float)(x)))
 # endif
+# ifdef __cplusplus
+#  ifdef isnan
+_GL_MATH_CXX_REAL_FLOATING_DECL_1 (isnan)
+#   undef isnan
+_GL_MATH_CXX_REAL_FLOATING_DECL_2 (isnan)
+#  endif
+# else
 /* Ensure isnan is a macro.  */
-# ifndef isnan
-#  define isnan isnan
+#  ifndef isnan
+#   define isnan isnan
+#  endif
 # endif
 #elif defined GNULIB_POSIXCHECK
 # if defined isnan
@@ -1102,7 +1496,7 @@ _GL_WARN_REAL_FLOATING_DECL (isnan);
 _GL_EXTERN_C int gl_signbitf (float arg);
 _GL_EXTERN_C int gl_signbitd (double arg);
 _GL_EXTERN_C int gl_signbitl (long double arg);
-#  if __GNUC__ >= 2 && !__STRICT_ANSI__
+#  if __GNUC__ >= 2 && !defined __STRICT_ANSI__
 #   define _GL_NUM_UINT_WORDS(type) \
       ((sizeof (type) + sizeof (unsigned int) - 1) / sizeof (unsigned int))
 #   if defined FLT_SIGNBIT_WORD && defined FLT_SIGNBIT_BIT && !defined gl_signbitf
@@ -1141,6 +1535,13 @@ _GL_EXTERN_C int gl_signbitl (long double arg);
     sizeof (x) == sizeof (double) ? gl_signbitd (x) : \
     gl_signbitf (x))
 # endif
+# ifdef __cplusplus
+#  ifdef signbit
+_GL_MATH_CXX_REAL_FLOATING_DECL_1 (signbit)
+#   undef signbit
+_GL_MATH_CXX_REAL_FLOATING_DECL_2 (signbit)
+#  endif
+# endif
 #elif defined GNULIB_POSIXCHECK
 # if defined signbit
 _GL_WARN_REAL_FLOATING_DECL (signbit);