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/*=========================================================================
*
* Copyright NumFOCUS
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* https://www.apache.org/licenses/LICENSE-2.0.txt
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*=========================================================================*/
#ifndef itkCopy_h
#define itkCopy_h
namespace itk
{
/** Returns a copy of its argument. Primarily used to make the act of copying (typically involving a copy-constructor
* call) explicit, and to avoid warnings like:
*
* - Microsoft Visual Studio 2022, IntelliSense Code Linter [lnt-accidental-copy] "`auto` doesn't deduce references. A
* possibly unintended copy is being made" (https://learn.microsoft.com/en-us/cpp/ide/lnt-accidental-copy)
* - Microsoft Visual Studio 2022, Warning C26820, "This is a potentially expensive copy operation. Consider using a
* reference unless a copy is required (p.9)" (https://learn.microsoft.com/en-us/cpp/code-quality/c26820?view=msvc-170)
* - Synopsys Coverity 2023.6.2, "CID 331225: Performance inefficiencies (AUTO_CAUSES_COPY)", "Using the `auto`
* keyword without an `&` causes the copy of an object...".
* - SonarSource static code analysis, "Unnecessary expensive copy should be avoided when using `auto` as a placeholder
* type", "Avoid this unnecessary copy by using a "const" reference. (cpp:S6032)",
* https://rules.sonarsource.com/cpp/RSPEC-6032/
*
* Example:
\code
const auto possiblyUnintendedCopy = image->GetRequestedRegion(); // Warning!
const auto intendedCopy = Copy(image->GetRequestedRegion()); // OK, no warning :-)
const auto [index, size] = Copy(image->GetRequestedRegion()); // OK, no warning :-)
\endcode
*
* \note In general, it is up to the programmer to choose between doing a copy and using a reference, of course. `Copy`
should only be used when doing a copy is preferred over using a reference.
*/
template <typename T>
[[nodiscard]] constexpr T
Copy(const T & original)
{
// May call the copy-constructor of `T`.
return original;
}
} // namespace itk
#endif // itkCopy_h
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