CxxUtils: Add minmax_transformed_element.h

Add [min,max]_transformed_element to return the minimum or maximum transformed element from a range along with its iterator. In principle this can be implemented using C++20 ranges, but then its difficult to avoid having the transformation evaluated multiple times per element.

This merge request affects 1 package:

• Control/CxxUtils

This merge request affects 4 files:

• Control/CxxUtils/CMakeLists.txt
• Control/CxxUtils/CxxUtils/minmax_transformed_element.h
• Control/CxxUtils/share/minmax_transformed_element_test.ref
• Control/CxxUtils/test/minmax_transformed_element_test.cxx

Adding @ssnyder as watcher

added Core main review-pending-level-1 labels

CI Result SUCCESS (hash 61fb62a9)

	Athena	AthSimulation	AthGeneration	AnalysisBase	AthAnalysis	DetCommon
externals
cmake
make
tests

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Athena: number of compilation errors 0, warnings 0
AthSimulation: number of compilation errors 0, warnings 0
AthGeneration: number of compilation errors 0, warnings 0
AnalysisBase: number of compilation errors 0, warnings 0
AthAnalysis: number of compilation errors 0, warnings 0
DetCommon: number of compilation errors 0, warnings 0
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added review-approved label and removed review-pending-level-1 label

merged

mentioned in commit 56ed445e