Aug 4, 2025 · The stringizing operator (#) is a preprocessor operator that causes the corresponding actual argument to be enclosed in double quotation marks. When the # operator is placed before an …

Jun 21, 2024 · Returns a value of type std::size_t that represents the hash value of key. For two parameters k1 and k2 that are equal, std::hash<Key>()(k1)==std::hash<Key>()(k2).

Aug 3, 2021 · The double-number-sign or token-pasting operator (##), which is sometimes called the merging or combining operator, is used in both object-like and function-like macros.

These operators are used to manipulate tokens during macro expansion. The " #" operator converts a macro parameter into a string literal, while the " ##" operator concatenates two tokens into a single …

21 The ## in # ## # acts like an escape sequence in this expression. It concatenates the leftmost and the rightmost # to finally produce the token ##. Simply defining the macro as ## would cause an error …

It is often useful to merge two tokens into one while expanding macros. This is called token pasting or token concatenation. The ‘ ## ’ preprocessing operator performs token pasting.

Sep 7, 2025 · Definition and various types of operators in computer programming. How operators manipulate values and examples and related terms to enhance your understanding.

Demonstrates creation of a hash function for a user defined type. Using this as a template parameter for std::unordered_map, std::unordered_set, etc. also requires specialization of std::equal_to.

Instances of this function object satisfy Hash. In particular, they define an operator() const that: Accepts a single parameter of type Key. Returns a value of type std::size_t that represents the hash value of …

Aug 3, 2021 · The number-sign or "stringizing" operator (#) converts macro parameters to string literals without expanding the parameter definition. It's used only with macros that take arguments.