Fix warnings

include/fmt/safe-duration-cast.h

@@ -271,7 +271,7 @@ To safe_duration_cast(std::chrono::duration<FromRep, FromPeriod> from,
       ec = 1;
       return {};
     }
-    count *= Factor::num;
+    count *= static_cast<IntermediateRep>(Factor::num);
   }
 
   // this can't go wrong, right? den>0 is checked earlier.

test/scan.h

@@ -167,7 +167,7 @@ struct scan_handler : error_handler {
   }
 
   void on_arg_id() { on_arg_id(next_arg_id_++); }
-  void on_arg_id(unsigned id) {
+  void on_arg_id(int id) {
     if (id >= args_.size) on_error("argument index out of range");
     arg_ = args_.data[id];
   }

test/std-format-test.cc

@@ -107,7 +107,8 @@ template <> struct std::formatter<S> {
   // Parses a width argument id in the format { <digit> }.
   constexpr auto parse(format_parse_context& ctx) {
     auto iter = ctx.begin();
-    auto get_char = [&]() { return iter != ctx.end() ? *iter : 0; };
+    // auto get_char = [&]() { return iter != ctx.end() ? *iter : 0; };
+    auto get_char = [&]() { return iter != ctx.end() ? *iter : '\0'; };
     if (get_char() != '{') return iter;
     ++iter;
     char c = get_char();
@@ -124,7 +125,9 @@ template <> struct std::formatter<S> {
         [](auto value) -> int {
           if constexpr (!is_integral_v<decltype(value)>)
             throw format_error("width is not integral");
-          else if (value < 0 || value > numeric_limits<int>::max())
+          // else if (value < 0 || value > numeric_limits<int>::max())
+          else if (fmt::internal::is_negative(value) < 0 ||
+                   value > numeric_limits<int>::max())
             throw format_error("invalid width");
           else
             return value;