[LyX/master] Require gcc 4.6

[Georg Baum]

commit e307944d18afe743c4c26dee2dc281c490617800
Author: Georg Baum <b...@lyx.org>
Date:   Wed Jun 15 22:04:51 2016 +0200

    Require gcc 4.6
    
    See also 5de30b1210a

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 68845e3..bb71599 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -272,8 +272,8 @@ if(UNIX OR MINGW)
          execute_process(COMMAND ${CMAKE_CXX_COMPILER} -dumpversion 
OUTPUT_VARIABLE GCC_VERSION OUTPUT_STRIP_TRAILING_WHITESPACE)
          message(STATUS "Using GCC version ${GCC_VERSION}")
          if(GCC_VERSION VERSION_LESS 4.9)
-                 if(GCC_VERSION VERSION_LESS 4.3)
-                         message(FATAL_ERROR "gcc >= 4.3 is required.")
+                 if(GCC_VERSION VERSION_LESS 4.6)
+                         message(FATAL_ERROR "gcc >= 4.6 is required.")
                  endif()
                  # <regex> in gcc is unusable in versions less than 4.9.0
                  # see https://gcc.gnu.org/bugzilla/show_bug.cgi?id=53631
diff --git a/INSTALL b/INSTALL
index a3cf93e..5e75f61 100644
--- a/INSTALL
+++ b/INSTALL
@@ -49,7 +49,7 @@ Requirements
 
 First of all, you will need a recent C++ compiler, where recent means
 that the compilers are close to C++11 standard conforming like gcc (at
-least 4.3) or clang.
+least 4.6) or clang.
 
 LyX makes great use of the C++ Standard Template Library (STL).
 This means that gcc users will have to install the relevant libstdc++
diff --git a/config/lyxinclude.m4 b/config/lyxinclude.m4
index bb7910a..c43ae99 100644
--- a/config/lyxinclude.m4
+++ b/config/lyxinclude.m4
@@ -209,7 +209,7 @@ AC_DEFUN([LYX_CXX_USE_REGEX],
        dnl <regex> in gcc is unusable in versions less than 4.9.0
        dnl see https://gcc.gnu.org/bugzilla/show_bug.cgi?id=53631
        case $gxx_version in
-         4.3*|4.4*|4.5*|4.6*|4.7*|4.8*) lyx_std_regex=no ;;
+         4.6*|4.7*|4.8*) lyx_std_regex=no ;;
          *) ;;
        esac
      fi
@@ -355,8 +355,8 @@ if test x$GXX = xyes; then
       AM_CPPFLAGS="$AM_CPPFLAGS -Wall -Wextra"
   fi
   case $gxx_version in
-      2.*|3.*) AC_ERROR([gcc >= 4.3 is required]);;
-      4.0*|4.1*|4.2*) AC_ERROR([gcc >= 4.3 is required]);;
+      2.*|3.*) AC_ERROR([gcc >= 4.6 is required]);;
+      4.0*|4.1*|4.2*|4.3*|4.4*|4.5*) AC_ERROR([gcc >= 4.6 is required]);;
   esac
   if test x$enable_stdlib_debug = xyes ; then
     dnl FIXME: for clang/libc++, one should define _LIBCPP_DEBUG2=0
@@ -370,7 +370,7 @@ if test x$GXX = xyes; then
     esac
   fi
     case $gxx_version in
-      4.3*|4.4*|4.5*|4.6*)
+      4.6*)
         dnl Note that this will define __GXX_EXPERIMENTAL_CXX0X__.
         dnl The source code relies on that.
         cxx11_flags="-std=c++0x";;