resolves #104: fix clang compiler error

provide a local typedef instead of using a pure anonymous struct

also fix inconsistent whitespace

src/log.h

@@ -38,7 +38,8 @@ namespace _ {
     }
     template<int N, int...I>
     static constexpr decltype(auto) static_alloc_str_impl(const char* str, std::integer_sequence<int, I...>) {
-		return (struct {char buf[N+1];}) {str[I]..., 0};
+        typedef struct {char buf[N+1];} static_null_terminated;
+        return (static_null_terminated) {str[I]..., '\0'};
     }
     template<int N>
     static constexpr decltype(auto) static_alloc_str(const char* str) {