std::experimental::ranges::tag::in, in1, in2, out, out1, out2, fun, min, max, begin, end

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Technical specifications
Filesystem library (filesystem TS)
Library fundamentals (library fundamentals TS)
Library fundamentals 2 (library fundamentals TS v2)
Library fundamentals 3 (library fundamentals TS v3)
Extensions for parallelism (parallelism TS)
Extensions for parallelism 2 (parallelism TS v2)
Extensions for concurrency (concurrency TS)
Extensions for concurrency 2 (concurrency TS v2)
Concepts (concepts TS)
Ranges (ranges TS)
Reflection (reflection TS)
Mathematical special functions (special functions TR)
 
 
General utilities library
Utility components
Function objects
Metaprogramming and type traits
Tagged pairs and tuples
                          
tag specifiers
                                      
                          
 
struct in { /* implementation-defined */ };

struct in1 { /* implementation-defined */ };
struct in2 { /* implementation-defined */ };
struct out { /* implementation-defined */ };
struct out1 { /* implementation-defined */ };
struct out2 { /* implementation-defined */ };
struct fun { /* implementation-defined */ };
struct min { /* implementation-defined */ };
struct max { /* implementation-defined */ };
struct begin { /* implementation-defined */ };

struct end { /* implementation-defined */ };
(ranges TS)

These classes are TagSpecifiers for use with ranges::tagged.

The name of a specifier is also the element name it corresponds to. For instance, ranges::tagged<std::pair<int, int>, tag::min, tag::max> provides a set of named accessors named min and a set of named accessors named max.