Argument Promotion Rules and Implicit Conversions1

1. Promotions and conversions are complex topics discussed in Section 4 and the beginning of Section 5 of the C++ standard. You can purchase a copy of the standard at

Sometimes, argument values that do not correspond precisely to the parameter types in the function prototype can be converted by the compiler to the proper type before the function is called. These conversions occur as specified by C++’s promotion rules. The promotion rules indicate the implicit conversions that the compiler can perform between fundamental types. An int can be converted to a double. A double can also be converted to an int but the fractional part of the double value is truncated. Keep ...

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