NotNull

An of a reference type T never being null.

* Must be initialized when declared.

* Can never be assigned the null literal (compile time error).

* If assigned a null value at runtime an exception will be thrown.

NotNull!T can be substituted for T at any time, but T cannot become NotNull without some attention: either declaring NotNull!T, or using the convenience function, enforceNotNull!T.

Condition: T must be a reference type.

struct NotNull (

) if (

is(T == class) ||

is(T == interface)

is(T == U*,

) &&

__traits(isScalar, T)

) {

import std.traits : isAssignable;;

this();

typeof(this) opAssign(NotNull!U rhs);

bool opCast();

this(T value);

this(typeof(null) );

typeof(this) opAssign(typeof(null) );

inout(T) get [@property getter];

version(none)

NotNull!U opCast();

import std.traits : BaseClassesTuple;;

version(none)
version(none)
static if(is(T == class) && !is(T == Object))

NotNull!(BaseClassesTuple!T[0]) _valueHelper [@property getter];

version(none)
version(none)
static if(!(is(T == class) && !is(T == Object)))

inout(T) _valueHelper [@property getter];

}

Constructors

this this(): Undocumented in source.
this this(T value): Constructs with a runtime not null check (via assert()).
this this(typeof(null) ): Disable null construction.

Alias This

get

Members

Functions

opAssign typeof(this) opAssign(NotNull!U rhs): Assignment from NotNull inherited class rhs to NotNull base class this.
opAssign typeof(this) opAssign(typeof(null) ): Disable null assignment.
opCast bool opCast(): Undocumented in source. Be warned that the author may not have intended to support it.
opCast NotNull!U opCast(): Undocumented in source. Be warned that the author may not have intended to support it.

Properties

_valueHelper NotNull!(BaseClassesTuple!T[0]) _valueHelper [@property getter]: Undocumented in source. Be warned that the author may not have intended to support it.
_valueHelper inout(T) _valueHelper [@property getter]: Undocumented in source. Be warned that the author may not have intended to support it.
get inout(T) get [@property getter]: Undocumented in source. Be warned that the author may not have intended to support it.

Examples

int myInt;
NotNull!(int *) not_null = &myInt;
// you can now use variable not_null anywhere you would
// have used a regular int*, but with the assurance that
// it never stored null.