Use cfloat instead of float.h

It would be more consistent to use the C++ headers instead of the C ones.

example/daubechies_wavelets/daubechies_scaling_integer_grid.cpp

@@ -173,7 +173,7 @@ int main()
        << "#ifndef BOOST_MATH_DAUBECHIES_SCALING_INTEGER_GRID_HPP\n"
        << "#define BOOST_MATH_DAUBECHIES_SCALING_INTEGER_GRID_HPP\n"
        << "#include <array>\n"
-       << "#include <float.h>\n"
+       << "#include <cfloat>\n"
        << "#include <boost/config.hpp>\n"
        << "/*\n"
        << "In order to keep the character count as small as possible and speed up\n"

include/boost/math/cstdfloat/cstdfloat_types.hpp

@@ -12,14 +12,14 @@
 #ifndef BOOST_MATH_CSTDFLOAT_TYPES_2014_01_09_HPP_
   #define BOOST_MATH_CSTDFLOAT_TYPES_2014_01_09_HPP_
 
-  #include <float.h>
+  #include <cfloat>
   #include <limits>
   #include <boost/math/tools/config.hpp>
 
   // This is the beginning of the preamble.
 
   // In this preamble, the preprocessor is used to query certain
-  // preprocessor definitions from <float.h>. Based on the results
+  // preprocessor definitions from <cfloat>. Based on the results
   // of these queries, an attempt is made to automatically detect
   // the presence of built-in floating-point types having specified
   // widths. These are *thought* to be conformant with IEEE-754,

include/boost/math/special_functions/detail/daubechies_scaling_integer_grid.hpp

@@ -9,7 +9,7 @@
 #ifndef BOOST_MATH_DAUBECHIES_SCALING_INTEGER_GRID_HPP
 #define BOOST_MATH_DAUBECHIES_SCALING_INTEGER_GRID_HPP
 #include <array>
-#include <float.h>
+#include <cfloat>
 #include <boost/math/tools/config.hpp>
 /*
 In order to keep the character count as small as possible and speed up

include/boost/math/special_functions/fpclassify.hpp

@@ -77,7 +77,7 @@ is used.
 */
 
 #if defined(_MSC_VER) || defined(BOOST_BORLANDC)
-#include <float.h>
+#include <cfloat>
 #endif
 #ifdef BOOST_MATH_USE_FLOAT128
 #ifdef __has_include

test/test_next.cpp

@@ -22,7 +22,7 @@
 
 #if !defined(_CRAYC) && !defined(__CUDACC__) && (!defined(__GNUC__) || (__GNUC__ > 3) || ((__GNUC__ == 3) && (__GNUC_MINOR__ > 3)))
 #if (defined(_M_IX86_FP) && (_M_IX86_FP >= 2)) || defined(__SSE2__) || defined(TEST_SSE2)
-#include <float.h>
+#include <cfloat>
 #include "xmmintrin.h"
 #define TEST_SSE2
 #endif