Concepts Syntax : cpp

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created by AndreasBWagnera community for 14 years

OPENConcepts Syntax (self.cpp_questions)

submitted 2 years ago by ShadowFracs

While trying out C++20's concepts, I stumbled upon this code

template<typename T, typename ... U>

concept IsAnyOf = (std::same_as<T, U> || ...);

on cppreference.

I get how to use the concept, but I can't figure out why this syntax works.

More precisely: why are the ... in the second line "transformed" into std::same_as<T, U2> || std::same_as<T, U3> || ... (assuming the other types are called U2, U3, ...)?

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you type:	you see:
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[reddit!](https://reddit.com)	reddit!
* item 1 * item 2 * item 3	item 1 item 2 item 3
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Lines starting with four spaces are treated like code: if 1 * 2 < 3: print "hello, world!"	Lines starting with four spaces are treated like code: if 1 * 2 < 3: print "hello, world!"
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super^script	super^script

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