From addf799040e8f0cefbe42ca1a22787802a969077 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Martin=20Ho=C5=99e=C5=88ovsk=C3=BD?=
 <martin.horenovsky@gmail.com>
Date: Fri, 6 Sep 2019 13:08:44 +0200
Subject: [PATCH] Workaround missing std::nextafter in uClibc

Luckily, the rest of C++11 features seem to be supported...

Closes #1739
---
 docs/configuration.md                         |  3 ++-
 .../internal/catch_compiler_capabilities.h    |  8 ++++++
 include/internal/catch_matchers_floating.cpp  | 25 +++++++++++++++++++
 include/internal/catch_matchers_floating.h    |  3 ---
 4 files changed, 35 insertions(+), 4 deletions(-)

diff --git a/docs/configuration.md b/docs/configuration.md
index 8726415a4e..8f0f9d008e 100644
--- a/docs/configuration.md
+++ b/docs/configuration.md
@@ -156,8 +156,9 @@ by using `_NO_` in the macro, e.g. `CATCH_CONFIG_NO_CPP17_UNCAUGHT_EXCEPTIONS`.
     CATCH_CONFIG_ENABLE_BENCHMARKING        // Enables the integrated benchmarking features (has a significant effect on compilation speed)
     CATCH_CONFIG_USE_ASYNC                  // Force parallel statistical processing of samples during benchmarking
     CATCH_CONFIG_ANDROID_LOGWRITE           // Use android's logging system for debug output
+    CATCH_CONFIG_GLOBAL_NEXTAFTER           // Use nextafter{,f,l} instead of std::nextafter
 
-> `CATCH_CONFIG_ANDROID_LOGWRITE` was [introduced](https://github.com/catchorg/Catch2/issues/1743) in Catch X.Y.Z
+> `CATCH_CONFIG_ANDROID_LOGWRITE` and `CATCH_CONFIG_GLOBAL_NEXTAFTER` were [introduced](https://github.com/catchorg/Catch2/issues/1743) in Catch X.Y.Z
 
 Currently Catch enables `CATCH_CONFIG_WINDOWS_SEH` only when compiled with MSVC, because some versions of MinGW do not have the necessary Win32 API support.
 
diff --git a/include/internal/catch_compiler_capabilities.h b/include/internal/catch_compiler_capabilities.h
index 7934e7fae6..3460c81482 100644
--- a/include/internal/catch_compiler_capabilities.h
+++ b/include/internal/catch_compiler_capabilities.h
@@ -197,6 +197,10 @@
     #define CATCH_CONFIG_COLOUR_NONE
 #endif
 
+#if defined(__UCLIBC__)
+#define CATCH_INTERNAL_CONFIG_GLOBAL_NEXTAFTER
+#endif
+
 ////////////////////////////////////////////////////////////////////////////////
 // Check if string_view is available and usable
 // The check is split apart to work around v140 (VS2015) preprocessor issue...
@@ -306,6 +310,10 @@
 #  define CATCH_CONFIG_ANDROID_LOGWRITE
 #endif
 
+#if defined(CATCH_INTERNAL_CONFIG_GLOBAL_NEXTAFTER) && !defined(CATCH_CONFIG_NO_GLOBAL_NEXTAFTER) && !defined(CATCH_CONFIG_GLOBAL_NEXTAFTER)
+#  define CATCH_CONFIG_GLOBAL_NEXTAFTER
+#endif
+
 #if !defined(CATCH_INTERNAL_SUPPRESS_PARENTHESES_WARNINGS)
 #   define CATCH_INTERNAL_SUPPRESS_PARENTHESES_WARNINGS
 #   define CATCH_INTERNAL_UNSUPPRESS_PARENTHESES_WARNINGS
diff --git a/include/internal/catch_matchers_floating.cpp b/include/internal/catch_matchers_floating.cpp
index d001b751cb..69a451c09e 100644
--- a/include/internal/catch_matchers_floating.cpp
+++ b/include/internal/catch_matchers_floating.cpp
@@ -11,13 +11,16 @@
 #include "catch_to_string.hpp"
 #include "catch_tostring.h"
 
+#include <cmath>
 #include <cstdlib>
 #include <cstdint>
 #include <cstring>
 #include <sstream>
+#include <type_traits>
 #include <iomanip>
 #include <limits>
 
+
 namespace Catch {
 namespace Matchers {
 namespace Floating {
@@ -77,10 +80,32 @@ bool almostEqualUlps(FP lhs, FP rhs, int maxUlpDiff) {
     return ulpDiff <= maxUlpDiff;
 }
 
+#if defined(CATCH_CONFIG_GLOBAL_NEXTAFTER)
+
+namespace Catch {
+    float nextafter(float x, float y) {
+        return ::nextafterf(x, y);
+    }
+
+    double nextafter(double x, double y) {
+        return ::nextafter(x, y);
+    }
+
+    long double nextafter(long double x, long double y) {
+        return ::nextafterl(x, y);
+    }
+} // end namespace Catch
+
+#endif
+
 template <typename FP>
 FP step(FP start, FP direction, int steps) {
     for (int i = 0; i < steps; ++i) {
+#if defined(CATCH_CONFIG_GLOBAL_NEXTAFTER)
+        start = Catch::nextafter(start, direction);
+#else
         start = std::nextafter(start, direction);
+#endif
     }
     return start;
 }
diff --git a/include/internal/catch_matchers_floating.h b/include/internal/catch_matchers_floating.h
index ee077526b6..3c1ceb072b 100644
--- a/include/internal/catch_matchers_floating.h
+++ b/include/internal/catch_matchers_floating.h
@@ -9,9 +9,6 @@
 
 #include "catch_matchers.h"
 
-#include <type_traits>
-#include <cmath>
-
 namespace Catch {
 namespace Matchers {