Replace SFINAE with concepts (#5361)

Concepts are cleaner to use and result in much better error messages for incorrect template use.

ntcore/src/main/native/cpp/net/WireDecoder.cpp

@@ -9,6 +9,7 @@
 #include <fmt/format.h>
 #include <wpi/Logger.h>
 #include <wpi/SpanExtras.h>
+#include <wpi/concepts.h>
 #include <wpi/json.h>
 #include <wpi/mpack.h>
 
@@ -104,12 +105,10 @@ static bool ObjGetStringArray(wpi::json::object_t& obj, std::string_view key,
 #endif
 
 template <typename T>
+  requires(std::same_as<T, ClientMessageHandler> ||
+           std::same_as<T, ServerMessageHandler>)
 static void WireDecodeTextImpl(std::string_view in, T& out,
                                wpi::Logger& logger) {
-  static_assert(std::is_same_v<T, ClientMessageHandler> ||
-                    std::is_same_v<T, ServerMessageHandler>,
-                "T must be ClientMessageHandler or ServerMessageHandler");
-
   wpi::json j;
   try {
     j = wpi::json::parse(in);
@@ -150,7 +149,7 @@ static void WireDecodeTextImpl(std::string_view in, T& out,
         goto err;
       }
 
-      if constexpr (std::is_same_v<T, ClientMessageHandler>) {
+      if constexpr (std::same_as<T, ClientMessageHandler>) {
         if (*method == PublishMsg::kMethodStr) {
           // name
           auto name = ObjGetString(*params, "name", &error);
@@ -302,7 +301,7 @@ static void WireDecodeTextImpl(std::string_view in, T& out,
           error = fmt::format("unrecognized method '{}'", *method);
           goto err;
         }
-      } else if constexpr (std::is_same_v<T, ServerMessageHandler>) {
+      } else if constexpr (std::same_as<T, ServerMessageHandler>) {
         if (*method == AnnounceMsg::kMethodStr) {
           // name
           auto name = ObjGetString(*params, "name", &error);

ntcore/src/main/native/include/networktables/NetworkTableValue.h

@@ -12,10 +12,11 @@
 #include <span>
 #include <string>
 #include <string_view>
-#include <type_traits>
 #include <utility>
 #include <vector>
 
+#include <wpi/concepts.h>
+
 #include "ntcore_c.h"
 
 namespace nt {
@@ -377,11 +378,10 @@ class Value final {
    *             time)
    * @return The entry value
    */
-  template <typename T,
-            typename std::enable_if<std::is_same<T, std::string>::value>::type>
+  template <std::same_as<std::string> T>
   static Value MakeString(T&& value, int64_t time = 0) {
     Value val{NT_STRING, time, private_init{}};
-    auto data = std::make_shared<std::string>(std::forward(value));
+    auto data = std::make_shared<std::string>(std::forward<T>(value));
     val.m_val.data.v_string.str = const_cast<char*>(data->c_str());
     val.m_val.data.v_string.len = data->size();
     val.m_storage = std::move(data);
@@ -414,11 +414,10 @@ class Value final {
    *             time)
    * @return The entry value
    */
-  template <typename T, typename std::enable_if<
-                            std::is_same<T, std::vector<uint8_t>>::value>::type>
+  template <std::same_as<std::vector<uint8_t>> T>
   static Value MakeRaw(T&& value, int64_t time = 0) {
     Value val{NT_RAW, time, private_init{}};
-    auto data = std::make_shared<std::vector<uint8_t>>(std::forward(value));
+    auto data = std::make_shared<std::vector<uint8_t>>(std::forward<T>(value));
     val.m_val.data.v_raw.data = const_cast<uint8_t*>(data->data());
     val.m_val.data.v_raw.size = data->size();
     val.m_storage = std::move(data);

ntcore/src/test/native/cpp/net/ServerImplTest.cpp

@@ -8,6 +8,8 @@
 #include <string_view>
 #include <vector>
 
+#include <wpi/concepts.h>
+
 #include "../MockLogger.h"
 #include "../PubSubOptionsMatcher.h"
 #include "../SpanMatcher.h"
@@ -99,12 +101,12 @@ static std::vector<uint8_t> EncodeServerBinary(const T& msgs) {
   std::vector<uint8_t> data;
   wpi::raw_uvector_ostream os{data};
   for (auto&& msg : msgs) {
-    if constexpr (std::is_same_v<typename T::value_type, net::ServerMessage>) {
+    if constexpr (std::same_as<typename T::value_type, net::ServerMessage>) {
       if (auto m = std::get_if<net::ServerValueMsg>(&msg.contents)) {
         net::WireEncodeBinary(os, m->topic, m->value.time(), m->value);
       }
-    } else if constexpr (std::is_same_v<typename T::value_type,
-                                        net::ClientMessage>) {
+    } else if constexpr (std::same_as<typename T::value_type,
+                                      net::ClientMessage>) {
       if (auto m = std::get_if<net::ClientValueMsg>(&msg.contents)) {
         net::WireEncodeBinary(os, Handle{m->pubHandle}.GetIndex(),
                               m->value.time(), m->value);