Workaround various icc bugs (#822)

include/fmt/printf.h

@@ -337,7 +337,9 @@ struct printf_formatter {
 /** This template formats data and writes the output to a writer. */
 template <typename OutputIt, typename Char, typename ArgFormatter>
 class basic_printf_context :
-  private internal::context_base<
+  // Inherit publicly as a workaround for the icc bug
+  // https://software.intel.com/en-us/forums/intel-c-compiler/topic/783476.
+  public internal::context_base<
     OutputIt, basic_printf_context<OutputIt, Char, ArgFormatter>, Char> {
  public:
   /** The character type for the output. */

test/CMakeLists.txt

@@ -123,7 +123,10 @@ else ()
 endif ()
 
 # Test that the library can be compiled with exceptions disabled.
+# -fno-exception is broken in icc: https://github.com/fmtlib/fmt/issues/822.
+if (NOT CMAKE_CXX_COMPILER_ID STREQUAL "Intel")
   check_cxx_compiler_flag(-fno-exceptions HAVE_FNO_EXCEPTIONS_FLAG)
+endif ()
 if (HAVE_FNO_EXCEPTIONS_FLAG)
   add_library(noexception-test ../src/format.cc)
   target_include_directories(