Cannot access trait constant %s::%s directly

Description

Traits cannot be used indepently from a host class. They must be used inside a class, with the use keyword.

It is also not possible to call a method or a property on a trait.

Trait constants were introduced after direct access to trait features was banned, so there was no time where accessing a trait constant was possible, unlike trait properties or methods.

Example

<?php

trait T {
	public static const C = 1;
}

echo T::C;

?>

Literal Examples

• Cannot access trait constant T::C directly

Alternatives

• Use the trait in a class and access its features.
• Convert the trait into a class and access its features.

Related error messages

• accessing-static-trait-property-%s::$%s-is-deprecated
• calling-static-trait-method-%s::%s-is-deprecated
• traits-cannot-have-constants
• accessing-static-trait-property-%s::$%s-is-deprecated,-it-should-only-be-accessed-on-a-class-using-the-trait

In previous PHP versions, this error message used to be :ref:traits-cannot-have-constants.