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Page 548 someInt <= someFloat The value of someInt is temporarily coerced to floating point representation before the comparison takes place. The only difference between arithmetic expressions and relational expressions is that the resulting type of a relational expression is always intthe value 1 (true) or 0 (false). Promotion (Widening) The conversion of a value from a lower type to a higher type according to a programming language's precedence of data types. Here is a table that describes the result of promoting a value from one simple type to another in C++: From To Result of Promotion double long double Same value, occupying more memory space float double Same value, occupying more memory space Integral type Floating point type Floating point equivalent of the integer value; fractional part is zero Integral type Its unsigned counterpart Same value, if original number is nonnegative; a radically different positive number, if original number is negative Signed integral type Longer signed integral type Same value, occupying more memory space unsigned integral type Longer integral type (either signed or unsigned) Same nonnegative value, occupying more memory space NOTE: The result of promoting a char to an int is compiler-dependent. Some compilers treat char as unsigned char, so promotion always yields a nonnegative integer. With other compilers, char means signed char, so promotion of a negative value yields a negative integer. The note at the bottom of the table suggests a potential problem if you are trying to write a portable C++ program. If you use the char type only to store
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