uri: add fmt::formatter for uri and component

uri.cpp

@@ -8,6 +8,8 @@
 #include "./debug/warn.hpp"
 
 #include <fmt/ostream.h>
+#include <fmt/compile.h>
+#include <fmt/format.h>
 
 using cruft::uri;
 
@@ -341,7 +343,7 @@ cruft::uri::percent_decode (view<const char*> s)
 
 ///////////////////////////////////////////////////////////////////////////////
 static constexpr
-char const*
+std::string_view
 to_string (cruft::uri::component val)
 {
     switch (val) {
@@ -361,7 +363,27 @@ to_string (cruft::uri::component val)
 }
 
 
+////-----------------------------------------------------------------------------
+fmt::format_context::iterator
+fmt::formatter<cruft::uri::component>::format (
+    cruft::uri::component val,
+    format_context &ctx
+) const {
+    return formatter<string_view>::format(::to_string (val), ctx);
+}
 
+
+////-----------------------------------------------------------------------------
+fmt::format_context::iterator
+fmt::formatter<cruft::uri>::format (
+    cruft::uri const &val,
+    fmt::format_context &ctx
+) const {
+    return formatter<string_view>::format (val.value (), ctx);
+}
+
+
+//-----------------------------------------------------------------------------
 std::ostream&
 cruft::operator<< (std::ostream &os, cruft::uri::component c)
 {
@@ -378,26 +400,6 @@ cruft::operator<< (std::ostream &os, cruft::uri const &val)
     return os;
 }
 
-//-----------------------------------------------------------------------------
-fmt::format_context::iterator
-fmt::formatter<cruft::uri::component>::format (
-    cruft::uri::component val,
-    fmt::format_context &ctx
-) const {
-    return fmt::formatter<std::string>::format (::to_string (val), ctx);
-}
-
-
-//-----------------------------------------------------------------------------
-fmt::format_context::iterator
-fmt::formatter<cruft::uri>::format (
-    cruft::uri const &val,
-    fmt::format_context &ctx
-) const {
-    return fmt::formatter<std::string>::format (val.value (), ctx);
-}
-
-
 ///////////////////////////////////////////////////////////////////////////////
 static std::string
 merge (std::string_view base, std::string_view relative)

uri.hpp

@@ -160,15 +160,17 @@ namespace cruft {
 }
 
 
+// Don't use std::string_view here, fmtlib reimplements it as fmt::string_view.
 template <>
-struct fmt::formatter<cruft::uri> : public fmt::formatter<std::string> {
+struct fmt::formatter<cruft::uri> : public fmt::formatter<string_view> {
     format_context::iterator
     format (cruft::uri const&, format_context &ctx) const;
 };
 
 
-template <>
-struct fmt::formatter<cruft::uri::component> : public fmt::formatter<std::string> {
-    format_context::iterator
-    format (cruft::uri::component, format_context &ctx) const;
+// Don't use std::string_view here, fmtlib reimplements it as fmt::string_view.
+template <> struct fmt::formatter<cruft::uri::component>: formatter<string_view> {
+    // parse is inherited from formatter<string_view>.
+    fmt::format_context::iterator
+    format(cruft::uri::component c, format_context& ctx) const;
 };