Use std::string_view and fmtlib across all libraries (#3402)

- Twine, StringRef, Format, and NativeFormatting have been removed
- Logging now uses fmtlib style formatting
- Nearly all uses of wpi::outs/errs have been replaced with fmt::print() or
std::puts()/std::fputs() (for unformatted strings).
- A wpi/fmt/raw_ostream.h header has been added to enable
fmt::print() with wpi::raw_ostream

simulation/halsim_ws_client/src/main/native/cpp/HALSimWS.cpp

@@ -4,8 +4,10 @@
 
 #include "HALSimWS.h"
 
+#include <cstdio>
+
+#include <fmt/format.h>
 #include <wpi/SmallString.h>
-#include <wpi/raw_ostream.h>
 #include <wpi/uv/util.h>
 
 #include "HALSimWSClientConnection.h"
@@ -22,7 +24,7 @@ HALSimWS::HALSimWS(wpi::uv::Loop& loop, ProviderContainer& providers,
       m_providers(providers),
       m_simDevicesProvider(simDevicesProvider) {
   m_loop.error.connect([](uv::Error err) {
-    wpi::errs() << "HALSim WS Client libuv Error: " << err.str() << "\n";
+    fmt::print(stderr, "HALSim WS Client libuv Error: {}\n", err.str());
   });
 
   m_tcp_client = uv::Tcp::Create(m_loop);
@@ -50,7 +52,7 @@ bool HALSimWS::Initialize() {
     try {
       m_port = std::stoi(port);
     } catch (const std::invalid_argument& err) {
-      wpi::errs() << "Error decoding HALSIMWS_PORT (" << err.what() << ")\n";
+      fmt::print(stderr, "Error decoding HALSIMWS_PORT ({})\n", err.what());
       return false;
     }
   } else {
@@ -83,13 +85,12 @@ void HALSimWS::Start() {
         m_connect_timer->Start(uv::Timer::Time(kTcpConnectAttemptTimeout));
       });
 
-  m_tcp_client->closed.connect(
-      []() { wpi::outs() << "TCP connection closed\n"; });
+  m_tcp_client->closed.connect([]() { std::puts("TCP connection closed"); });
 
   // Set up the connection timer
-  wpi::outs() << "HALSimWS Initialized\n";
-  wpi::outs() << "Will attempt to connect to ws://" << m_host << ":" << m_port
-              << m_uri << "\n";
+  std::puts("HALSimWS Initialized");
+  fmt::print("Will attempt to connect to ws://{}:{}{}\n", m_host, m_port,
+             m_uri);
 
   // Set up the timer to attempt connection
   m_connect_timer->timeout.connect([this] { AttemptConnect(); });
@@ -102,7 +103,7 @@ void HALSimWS::Start() {
 void HALSimWS::AttemptConnect() {
   m_connect_attempts++;
 
-  wpi::outs() << "Connection Attempt " << m_connect_attempts << "\n";
+  fmt::print("Connection Attempt {}\n", m_connect_attempts);
 
   struct sockaddr_in dest;
   uv::NameToAddr(m_host, m_port, &dest);
@@ -167,6 +168,6 @@ void HALSimWS::OnNetValueChanged(const wpi::json& msg) {
       provider->OnNetValueChanged(msg.at("data"));
     }
   } catch (wpi::json::exception& e) {
-    wpi::errs() << "Error with incoming message: " << e.what() << "\n";
+    fmt::print(stderr, "Error with incoming message: {}\n", e.what());
   }
 }

simulation/halsim_ws_client/src/main/native/cpp/HALSimWSClientConnection.cpp

@@ -4,7 +4,9 @@
 
 #include "HALSimWSClientConnection.h"
 
-#include <wpi/raw_ostream.h>
+#include <cstdio>
+
+#include <fmt/format.h>
 #include <wpi/raw_uv_ostream.h>
 
 #include "HALSimWS.h"
@@ -17,29 +19,29 @@ void HALSimWSClientConnection::Initialize() {
   // Get a shared pointer to ourselves
   auto self = this->shared_from_this();
 
-  auto ws =
-      wpi::WebSocket::CreateClient(*m_stream, m_client->GetTargetUri(),
-                                   wpi::Twine{m_client->GetTargetHost()} + ":" +
-                                       wpi::Twine{m_client->GetTargetPort()});
+  auto ws = wpi::WebSocket::CreateClient(
+      *m_stream, m_client->GetTargetUri(),
+      fmt::format("{}:{}", m_client->GetTargetHost(),
+                  m_client->GetTargetPort()));
 
   ws->SetData(self);
 
   m_websocket = ws.get();
 
   // Hook up events
-  m_websocket->open.connect_extended([this](auto conn, wpi::StringRef) {
+  m_websocket->open.connect_extended([this](auto conn, auto) {
     conn.disconnect();
 
     if (!m_client->RegisterWebsocket(shared_from_this())) {
-      wpi::errs() << "Unable to register websocket\n";
+      std::fputs("Unable to register websocket\n", stderr);
       return;
     }
 
     m_ws_connected = true;
-    wpi::outs() << "HALSimWS: WebSocket Connected\n";
+    std::puts("HALSimWS: WebSocket Connected");
   });
 
-  m_websocket->text.connect([this](wpi::StringRef msg, bool) {
+  m_websocket->text.connect([this](auto msg, bool) {
     if (!m_ws_connected) {
       return;
     }
@@ -50,7 +52,7 @@ void HALSimWSClientConnection::Initialize() {
     } catch (const wpi::json::parse_error& e) {
       std::string err("JSON parse failed: ");
       err += e.what();
-      wpi::errs() << err << "\n";
+      fmt::print(stderr, "{}\n", err);
       m_websocket->Fail(1003, err);
       return;
     }
@@ -58,9 +60,9 @@ void HALSimWSClientConnection::Initialize() {
     m_client->OnNetValueChanged(j);
   });
 
-  m_websocket->closed.connect([this](uint16_t, wpi::StringRef) {
+  m_websocket->closed.connect([this](uint16_t, auto) {
     if (m_ws_connected) {
-      wpi::outs() << "HALSimWS: Websocket Disconnected\n";
+      std::puts("HALSimWS: Websocket Disconnected");
       m_ws_connected = false;
 
       m_client->CloseWebsocket(shared_from_this());
@@ -90,8 +92,8 @@ void HALSimWSClientConnection::OnSimValueChanged(const wpi::json& msg) {
                                   }
 
                                   if (err) {
-                                    wpi::errs() << err.str() << "\n";
-                                    wpi::errs().flush();
+                                    fmt::print(stderr, "{}\n", err.str());
+                                    std::fflush(stderr);
                                   }
                                 });
   });

simulation/halsim_ws_client/src/main/native/cpp/main.cpp

@@ -2,10 +2,10 @@
 // Open Source Software; you can modify and/or share it under the terms of
 // the WPILib BSD license file in the root directory of this project.
 
+#include <cstdio>
 #include <memory>
 
 #include <hal/Extensions.h>
-#include <wpi/raw_ostream.h>
 
 #include "HALSimWSClient.h"
 
@@ -19,7 +19,7 @@ __declspec(dllexport)
 #endif
 
     int HALSIM_InitExtension(void) {
-  wpi::outs() << "HALSim WS Client Extension Initializing\n";
+  std::puts("HALSim WS Client Extension Initializing");
 
   HAL_OnShutdown(nullptr, [](void*) { gClient.reset(); });
 
@@ -28,7 +28,7 @@ __declspec(dllexport)
     return -1;
   }
 
-  wpi::outs() << "HALSim WS Client Extension Initialized\n";
+  std::puts("HALSim WS Client Extension Initialized");
   return 0;
 }