How are constraints and concepts used in cppreference?

For the Concepts TS version of this feature, see here. Class templates, function templates, and non-template functions (typically members of class templates) may be associated with a constraint, which specifies the requirements on template arguments, which can be used to select the most appropriate function overloads and template specializations.
In addition, how are constraints related to non template functions?
Class templates, function templates, and non-template functions (typically members of class templates) may be associated with a constraint, which specifies the requirements on template arguments, which can be used to select the most appropriate function overloads and template specializations. Named sets of such requirements are called concepts.
Consequently, when is the constraint not satisfied in cppreference? If the substitution results in an invalid type or expression, the constraint is not satisfied. Otherwise, E, after any lvalue-to-rvalue conversion, shall be a prvalue constant expression of type bool , and the constraint is satisfied if and only if it evaluates to true.
Subsequently, how are the constraints associated with a declaration determined?
There are three types of constraints: The constraint associated with a declaration are determined by normalizing a logical AND expression whose operands are in the following order: the constraint expression introduced for each constrained template parameter, in order of appearance;
Accordingly, how are constraints introduced in order of appearance?
the constraint expression introduced for each constrained template parameter, in order of appearance; the constraint expression in the requires clause after the template parameter list; the constraint expression in the trailing requires clause. This order determines the order in which constraints are instantiated...

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When to use static assert in cppreference.com?

A static assert declaration may appear at namespace and block scope (as a block declaration) and inside a class body (as a member declaration) If bool_constexpr returns true, this declaration has no effect. Otherwise a compile-time error is issued, and the text of message, if any, is included in the diagnostic message.

How are namespaces declared in cppreference.com?

Namespaces. Symbols declared inside a namespace block are placed in a named scope that prevents them from being mistaken for identically-named symbols in other scopes. Multiple namespace blocks with the same name are allowed. All declarations within those blocks are declared in the named scope.

How is argument dependent lookup used in cppreference?

These function names are looked up in the namespaces of their arguments in addition to the scopes and namespaces considered by the usual unqualified name lookup . Argument-dependent lookup makes it possible to use operators defined in a different namespace. Example:

Where to find unnamed namespaces in cppreference?

3) Unnamed namespace definition. Its members have potential scope from their point of declaration to the end of the translation unit, and have internal linkage. 4) Namespace names (along with class names) can appear on the left hand side of the scope resolution operator, as part of qualified name lookup.

How are namespaces specialized in cppreference.com?

Each member of an inline namespace can be partially specialized , explicitly instantiated or explicitly specialized as if it were a member of the enclosing namespace. Qualified name lookup that examines the enclosing namespace will include the names from the inline namespaces even if the same name is present in the enclosing namespace.

How are elements compared using cppreference in std?

1) Elements are compared using operator< and the ranges must be sorted with respect to the same. 3) Elements are compared using the given binary comparison function comp and the ranges must be sorted with respect to the same. 2,4) Same as (1,3), but executed according to policy.

How to dereference an object in cppreference?

The types Type1 and Type2 must be such that objects of types InputIt1 and InputIt2 can be dereferenced and then implicitly converted to both Type1 and Type2 . - InputIt1, InputIt2 must meet the requirements of LegacyInputIterator . - OutputIt must meet the requirements of LegacyOutputIterator .

How to copy the sorted range in cppreference?

Copies the elements from the sorted range [first1, last1) which are not found in the sorted range [first2, last2) to the range beginning at d_first. The resulting range is also sorted.

How does std : : shared _ ptr work in cppreference?

std::shared_ptr is a smart pointer that retains shared ownership of an object through a pointer. Several shared_ptr objects may own the same object. The object is destroyed and its memory deallocated when either of the following happens:

When is a positive value in memcmp-cppreference?

0​ if all count bytes of lhs and rhs are equal. Positive value if the first differing byte in lhs is greater than the corresponding byte in rhs . This function reads object representations, not the object values, and is typically only meaningful for trivially-copyable objects with no padding.

How to use std : stoll in cppreference?

std:: stoi, std:: stol, std:: stoll Defined in header <string> int stoi( const std::string& str, std::s ... (1) long stol( const std::string& str, std:: ... (2) long long stoll( const std::string& str, ... (3)

How to define std : stod, std-stod-cppreference?

std:: stof, std:: stod, std:: stold Defined in header <string> float stof( const std::string& str, std: ... (1) double stod( const std::string& str, std ... (2) long double stold( const std::string& st ... (3)

How to define std's basic string for cppreference?

Defined in header <string> Type Definition std::string std::basic_string<char> std::wstring std::basic_string<wchar_t> std::u8string (C++20) std::basic_string<char8_t> std::u16string (C++11) std::basic_string<char16_t> 6 more rows ...

When to use emplace in cppreference.com?

Args > Inserts a new element into the container constructed in-place with the given args if there is no element with the key in the container. Careful use of emplace allows the new element to be constructed while avoiding unnecessary copy or move operations.

What happens to pair in emplace-cppreference function?

Returns a pair consisting of an iterator to the inserted element, or the already-existing element if no insertion happened, and a bool denoting whether the insertion took place ( true if insertion happened, false if it did not). If an exception is thrown by any operation, this function has no effect.

How does std : : vector work in cppreference?

std:: vector. std:: vector. 1) std::vector is a sequence container that encapsulates dynamic size arrays. The elements are stored contiguously, which means that elements can be accessed not only through iterators, but also using offsets to regular pointers to elements.

How are type traits used in cppreference.com?

This is the class returned by the typeid operator. Type traits defines a compile-time template-based interface to query or modify the properties of types. Attempting to specialize a template defined in the <type_traits> header results in undefined behavior, except that std::common_type may be specialized as described in its description .

Which is the iterator trait class in cppreference?

std::iterator_traits is the type trait class that provides uniform interface to the properties of LegacyIterator types. This makes it possible to implement algorithms only in terms of iterators. The class defines the following types: value_type - the type of the values that can be obtained by dereferencing the iterator.

How to obtain a pointer like type in cppreference?

The rebind member template alias makes it possible, given a pointer-like type that points to T, to obtain the same pointer-like type that points to U. For example, 0​

How does std : map work in cppreference?

(since C++17) std::map is a sorted associative container that contains key-value pairs with unique keys. Keys are sorted by using the comparison function Compare. Search, removal, and insertion operations have logarithmic complexity.