example

<?php
/**
 * Functionality for modifying and outputting breadcrumbs provided by Yoast.
 *
 * @package IPM
 */

namespace IPM\Breadcrumbs;

/**
 * Sets up this file with the WordPress API.
 *
 * @return void
 */
function load() {
	add_action( 'after_setup_theme', __NAMESPACE__ . '\\setup' );
}

/**
 * Register various methods with the WordPress API.
 *
 * @return void
 */
function setup() {
	add_action( 'ipm_content_top', __NAMESPACE__ . '\\display_breadcrumbs', 5 );
	add_filter( 'wp_head', __NAMESPACE__ . '\\maybe_hide_title' );
	add_filter( 'wpseo_breadcrumb_links', __NAMESPACE__ . '\\insert_breadcrumbs' );
}

/**
 * Display consistent breadcrumbs
 *
 * @action ipm_content_top
 * @todo build_futures removes this action. need to adjust to account for namespace
 * @return string
 */
function display_breadcrumbs() {
	if ( is_home() && ! is_paged() ) {
		return;
	} else {
		echo '<div class="custom-bread-crumb">';
		if ( function_exists( 'yoast_breadcrumb' ) ) {
			yoast_breadcrumb( '<div class="breadcrumb-trail">', '</div>' );
		}
		echo '</div><!-- .custom-bread-crumb -->';
	}
}

/**
 * Conditionally prevent output of title breadcrumb
 *
 * @param array $links Array of links.
 *
 * @return array
 */
function maybe_hide_title( $links ) {

	if ( is_singular( 'post' )
		|| ( function_exists( '\IPM\Special_Reports\is_special_report' ) && \IPM\Special_Reports\is_special_report() )
	) { ?>
		<!-- Hide last breadcrumb -->
		<style>
			.breadcrumb-trail .breadcrumb_last {
				display: none;
			}
		</style><?php
	}

	return $links;
}

/**
 * Alter the breadcrumb markup to add elements not naturally added by Yoast.
 *
 * @param array $links Array of link elements.
 *
 * @return array
 */
function insert_breadcrumbs( $links ) {
	if ( is_tax( 'ipm_hot_topics' ) ) {
		array_splice( $links, 1, 0, [
			[
				'text'       => '<a href="">Hot Topics</a>',
				'url'        => '',
				'allow_html' => true,
			],
		] );
	}

	return $links;
}