llvm-project/llvm/lib/Support/Optional.cpp
Pavel Labath 47e9a21d34 [ADT] Add streaming operators for llvm::Optional
Summary:
The operators simply print the underlying value or "None".

The trickier part of this patch is making sure the streaming operators
work even in unit tests (which was my primary motivation, though I can
also see them being useful elsewhere). Since the stream operator was a
template, implicit conversions did not kick in, and our gtest glue code
was explicitly introducing an implicit conversion to make sure other
implicit conversions do not kick in :P. I resolve that by specializing
llvm_gtest::StreamSwitch for llvm:Optional<T>.

Reviewers: sammccall, dblaikie

Reviewed By: sammccall

Subscribers: mgorny, dexonsmith, kristina, llvm-commits

Differential Revision: https://reviews.llvm.org/D56795

llvm-svn: 351548
2019-01-18 12:52:03 +00:00

16 lines
502 B
C++

//===- Optional.cpp - Optional values ---------------------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include "llvm/ADT/Optional.h"
#include "llvm/Support/raw_ostream.h"
llvm::raw_ostream &llvm::operator<<(raw_ostream &OS, NoneType) {
return OS << "None";
}