gave up and switched back to is_integral. Most things in to_string get converted implicitly anyways...

example/example.cpp

@@ -398,9 +398,9 @@ void attribute_example() {
     spdlog::info("EXPERIMENTAL: log with attributes");
     spdlog::clear_context();
     
-    short s = 0;
-    unsigned short us = 1;
-    const int& i = 2;
+    char s = 0;
+    int8_t us = 1;
+    const int16_t& i = 2;
     unsigned int ui = 3;
     long l = 4;
     unsigned long ul = 5;

include/spdlog/details/log_attr.h

@@ -16,13 +16,7 @@ struct is_string
 
 template<typename T>
 struct is_number : public std::integral_constant<bool, 
-    std::is_same<T, int>::value || std::is_same<T, unsigned int>::value 
-    || std::is_same<T, long>::value || std::is_same<T, unsigned long>::value 
-    || std::is_same<T, long long>::value || std::is_same<T, unsigned long long>::value
-
-    // shorts/chars get converted to int by to_string implicitly. Should we ignore chars but enforce shorts?
-    || std::is_convertible<T, int>::value || std::is_convertible<T, unsigned int>::value 
-
+    std::is_integral<T>::value
     // || std::is_floating_point<T>::value
 >
 {};