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

hal/src/main/native/cpp/ErrorHandling.cpp

@@ -2,8 +2,8 @@
 // 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 <fmt/format.h>
 #include <wpi/SmallString.h>
-#include <wpi/Twine.h>
 
 #include "hal/Errors.h"
 #include "hal/HALBase.h"
@@ -21,31 +21,30 @@ static LastErrorStorage& GetThreadLastError() {
 }
 
 namespace hal {
-void SetLastError(int32_t* status, const wpi::Twine& value) {
+void SetLastError(int32_t* status, std::string_view value) {
   LastErrorStorage& lastError = GetThreadLastError();
-  lastError.message.clear();
-  value.toVector(lastError.message);
+  lastError.message = value;
   lastError.status = *status;
   *status = HAL_USE_LAST_ERROR;
 }
 
-void SetLastErrorIndexOutOfRange(int32_t* status, const wpi::Twine& message,
+void SetLastErrorIndexOutOfRange(int32_t* status, std::string_view message,
                                  int32_t minimum, int32_t maximum,
                                  int32_t requested) {
-  SetLastError(status, message + "\n Status: " + wpi::Twine(*status) +
-                           "\n  Minimum: " + wpi::Twine(minimum) +
-                           " Maximum: " + wpi::Twine(maximum) +
-                           " Reequested: " + wpi::Twine(requested));
+  SetLastError(
+      status,
+      fmt::format("{}\n Status: {}\n  Minimum: {} Maximum: {} Requested: {}",
+                  message, *status, minimum, maximum, requested));
 }
 
-void SetLastErrorPreviouslyAllocated(int32_t* status, const wpi::Twine& message,
+void SetLastErrorPreviouslyAllocated(int32_t* status, std::string_view message,
                                      int32_t channel,
-                                     const wpi::Twine& previousAllocation) {
-  hal::SetLastError(
-      status,
-      message + " " + wpi::Twine(channel) +
-          " previously allocated.\nLocation of the previous allocation:\n" +
-          previousAllocation + "\nLocation of the current allocation:");
+                                     std::string_view previousAllocation) {
+  hal::SetLastError(status,
+                    fmt::format("{} {} previously allocated.\n"
+                                "Location of the previous allocation:\n{}\n"
+                                "Location of the current allocation:",
+                                message, channel, previousAllocation));
 }
 }  // namespace hal