downcast (adj)

a ventilation shaft through which air enters a mine

downcast (adj)

directed downward

"a downcast glance"

gloomy, grim, blue, depressed, dispirited, down(p), downcast, downhearted, down in the mouth, low, low-spirited (adj)

filled with melancholy and despondency

"gloomy at the thought of what he had to face"; "gloomy predictions"; "a gloomy silence"; "took a grim view of the economy"; "the darkening mood"; "lonely and blue in a strange city"; "depressed by the loss of his job"; "a dispirited and resigned expression on her face"; "downcast after his defeat"; "feeling discouraged and downhearted"

downcast (Noun)

A cast from supertype to subtype.

downcast (Verb)

To cast or throw up; to turn upward.

downcast (Verb)

To taunt; to reproach; to upbraid.

downcast (Verb)

To cast from supertype to subtype.

downcast (Adjective)

Looking downwards.

downcast (Adjective)

Feeling despondent.

downcast

In class-based programming, downcasting or type refinement is the act of casting a reference of a base class to one of its derived classes. In many programming languages, it is possible to check through type introspection to determine whether the type of the referenced object is indeed the one being cast to or a derived type of it, and thus issue an error if it is not the case. In other words, when a variable of the base class (parent class) has a value of the derived class (child class), downcasting is possible. Some languages, such as OCaml, disallow downcasting.