Fix handling of pointers in format string compilation and FMT_BUILTIN_TYPES=0

Author: vitaut

include/fmt/base.h

@@ -2258,8 +2258,11 @@ template <typename Context> class value {
       : pointer(const_cast<const void*>(x)) {}
   FMT_INLINE value(nullptr_t) : pointer(nullptr) {}
 
-  template <typename T, FMT_ENABLE_IF(std::is_pointer<T>::value ||
-                                      std::is_member_pointer<T>::value)>
+  template <typename T,
+            FMT_ENABLE_IF(
+                (std::is_pointer<T>::value ||
+                 std::is_member_pointer<T>::value) &&
+                !std::is_void<typename std::remove_pointer<T>::type>::value)>
   value(const T&) {
     // Formatting of arbitrary pointers is disallowed. If you want to format a
     // pointer cast it to `void*` or `const void*`. In particular, this forbids

test/no-builtin-types-test.cc

@@ -7,9 +7,10 @@
 
 #include "gtest/gtest.h"
 
-#if !defined(__GNUC__) || __GNUC__ >= 5
-#  define FMT_BUILTIN_TYPES 0
-#  include "fmt/format.h"
+#define FMT_BUILTIN_TYPES 0
+#include "fmt/compile.h"
+
+#if !FMT_GCC_VERSION || FMT_GCC_VERSION >= 500
 
 TEST(no_builtin_types_test, format) {
   EXPECT_EQ(fmt::format("{}", 42), "42");
@@ -22,4 +23,9 @@ TEST(no_builtin_types_test, double_is_custom_type) {
   EXPECT_EQ(fmt::format_args(args).get(0).type(),
             fmt::detail::type::custom_type);
 }
+
+TEST(no_builtin_types_test, format_pointer_compiled) {
+  const void* p = nullptr;
+  fmt::format(FMT_COMPILE("{:} {}"), 42, p);
+}
 #endif