1e99b1783d
Add a new version of the Result class that functions like the old
Result, but in case of an error, also encodes a string detailing the
error. This will allow us to write the following type of code:
Result<Foo> CreateFoo() {
if (...) {
return Error("errno=%d", errno());
}
return Foo(...);
}
auto foo = CreateFoo();
if (!foo) {
std::cerr << "error: " << foo.GetErrorMessage() << std::endl;
abort();
}
std::cout << "foo=" << *foo << std::endl;
This commit only adds the new Result class. A later change will replace
uses of the old version.
Test: make idmap2_tests
Change-Id: I674d8a06866402adedf85f8514400f25840d5eda
42 lines
1.1 KiB
C++
42 lines
1.1 KiB
C++
/*
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* Copyright (C) 2019 The Android Open Source Project
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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#include <cstdarg>
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#include "android-base/stringprintf.h"
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#include "idmap2/Result.h"
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namespace android::idmap2 {
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v2::Error::Error(const char* fmt, ...) {
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va_list ap;
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va_start(ap, fmt);
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base::StringAppendV(&msg_, fmt, ap);
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va_end(ap);
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}
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v2::Error::Error(const Error& parent, const char* fmt, ...) : msg_(parent.msg_) {
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msg_.append(" -> ");
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va_list ap;
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va_start(ap, fmt);
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base::StringAppendV(&msg_, fmt, ap);
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va_end(ap);
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}
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} // namespace android::idmap2
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