Go Generics 101 (2022/08/29)

Acknowledgments
About Go Generics 101
About Go Custom Generics
First Look of Custom Generics
	A generic type example
	An example of a method of a generic type
	A generic function example
	Generic functions could be viewed as simplified forms of methods of generic types
Constraints and Type Parameters
	Enhanced interface syntax
	Type sets and method sets
	More about the predeclared comparable constraint
	More requirements for union terms
	Type parameter lists
	Simplified constraint form
	Each type parameter is a distinct named type
	Composite type literals (unnamed types) containing type parameters are ordinary types
	The scopes of a type parameters
	More about generic type and function declarations
Generic Instantiations and Type Argument Inferences
	Generic type/function instantiations
	Type argument inferences for generic function instantiations
	Type argument inferences don't work for generic type instantiations
	Pass basic interface types as type arguments
	Pass type parameters as type arguments
	More about instantiated types
	About the instantiation syntax inconsistency between custom generics and built-in generics
Operations on Values of Type Parameter Types
	The type of a value used in a generic function must be a specified type
	Type parameters may be not used as types of (local) named constants
	The core type of a type
	A function is required to have a core type to be callable
	The type literal in a composite literal must have a core type
	An element index operation requires the container operand's type set may not include maps and non-maps at the same time
	A (sub)slice operation requires the container operand has a core type
	In a for-range loop, the ranged container is required to have a core type
	Type parameter involved conversions
	Type parameter involved assignments
	Calls to predeclared functions
	A call to the predeclared len or cap functions is valid if it is valid for all of the types in the type set of the argument
	A call to the predeclared new function has not extra requirements for its argument
	A call to the predeclared make function requires its first argument (the container type) has a core type
	A call to the predeclared delete function requires all types in the type set of its first argument have an identical key type
	A call to the predeclared close function requires all types in the type set of its argument are channel types
	Calls to predeclared complex, real and imag functions don't accept arguments of type parameter now
	About constraints with empty type sets
The Status Quo of Go Custom Generics
	Type declarations inside generic functions are not currently supported
	Generic type aliases are not supported currently
	Embedding type parameters in struct types is not allowed now
	The method set of a constraint is not calculated completely for some cases
	No ways to specific a field set for a constraint
	No ways to use common fields for a constraint if the constraint has not a core (struct) type
	Fields of values of type parameters are not accessible
	Type switches on values of type parameters are not supported now
	Generic methods are not supported
	There are no ways to construct a constraint which allows assignments involving types of unspecific underlying types
	There are no ways to construct a constraint which allows conversion involving types of unspecific underlying types