Missed Angular *ngVar directive (from https://stackoverflow.com/a/43172992/1847657)

ng-var.directive.ts

// tslint:disable:no-any directive-selector

import { Directive, Input, TemplateRef, ViewContainerRef } from '@angular/core';

/**
 * Declare a variable in the template.
 * Eg. <i *ngVar="false as variable">{{ variable | json }}</i>
 */
@Directive({selector: '[ngVar]'})
export class NgVarDirective {
  public context: any = {};

  constructor(
    private vcRef: ViewContainerRef,
    private templateRef: TemplateRef<any>,
  ) {}

  @Input()
  set ngVar(context: any) {
    this.context.$implicit = this.context.ngVar = context;
    this.updateView();
  }

  private updateView() {
    this.vcRef.clear();
    this.vcRef.createEmbeddedView(this.templateRef, this.context);
  }
}

If anyone cares, here is a version, that will retain the type of the variable inside the template:

import { Directive, Input, TemplateRef, ViewContainerRef } from '@angular/core';


interface VarContext<T> {
	$implicit: T;
	var: T;
}

/**
 * Declare a variable in the template.
 * Eg. <i *var="false as variable">{{ variable | json }}</i>
 */
@Directive({selector: '[var]'})
export class VarDirective<T = unknown> {
	public context: VarContext<T> = {} as any;

	constructor(
		private vcRef: ViewContainerRef,
		private templateRef: TemplateRef<any>,
	) {}

	@Input()
	set var(context: T) {
		this.context.$implicit = this.context.var = context;
		this.updateView();
	}

	private updateView() {
		this.vcRef.clear();
		this.vcRef.createEmbeddedView(this.templateRef, this.context);
	}

	static ngTemplateContextGuard<T>(dir: VarDirective<T>, ctx: any): ctx is VarContext<T> {
		return true;
	}
}