Type conversions

An expression of a given type is implicitly converted in the following situations:

• The expression is used as an operand of an arithmetic or logical operation.
• The expression is used as a condition in an if statement or an iteration statement (such as a for loop). The expression will be converted to a Boolean.
• The expression is used in a switch statement. The expression will be converted to an integral type.
• The expression is used as an initialization. This includes the following:
  • An assignment is made to an lvalue that has a different type than the assigned value.
  • A function is provided an argument value that has a different type than the parameter.
  • The value specified in the return statement of a function has a different type from the defined return type for the function.

You can perform explicit type conversions using a cast expression, as described in Cast expressions. The following sections discuss the conversions that are allowed by either implicit or explicit conversion, and the rules governing type promotions:

• Arithmetic conversions and promotions
• Lvalue-to-rvalue conversions
• Pointer conversions
• Reference conversions (C++ only)
• Qualification conversions (C++ only)
• Function argument conversions