from
The Free On-line Dictionary of Computing (8 July 2008)
implicit type conversion
coercion
<programming> (Or "coercion") The abilty of some {compilers}
to automatically insert {type} conversion {functions} where an
expression of one type is used in a context where another type
is expected.
A common example is coercion of {integers} to {reals} so that
an expression like sin(1) is compiled as sin(integerToReal(1))
where sin is of type Real -> Real.
A coercion is usually performed automatically by the compiler
whereas a {cast} is an {explicit type conversion} inserted by
the programmer.
See also {subtype}.
(1997-07-28)