mapit | web service to map postcodes

I am building a web application and using an ORM called norm. As such, I have an SQL database with a bunch of tables, all of which correspond to various Models that I have in nim. Often enough, they are in many-to-many relationships such as this:

I'd like to have some sort of structure/type/map which can contain std::function specialisations (to contain my callbacks) which have the type known at compile time, without having to do any sort of virtual inheritance or making all my types inherit from a base type.

e.g. I'd like GenericFunction in here to hold the std::function without erasing the known type, so I can get the type later on during the callback()

I have two leaflet maps which are loaded with geojson on the basis of a search button click. This shows some polygons with a style opacity 0.3 so you can see the street names under the polygons.

It works great except that any additional searches and loading of polygons starts to change the opacity of the polygon, making it more solid so you cant read the names of the streets under the polygon.

I try clearing the geojson layer before adding to the map, but the issue persists.

I have created a rough code pen of the issue here: https://codepen.io/joomkit/pen/xxXgLPJ?editors=1111

Essentially just click the search button to load the layer no need to fill the listener runs a function and gets static data.

I have tried various methods to remove layer. A second click on the search is meant to clear the layer and load a new one. In the example it's just reloading the original data but the opacity is clearly demonstrated.

Main code is also below.

I have a function:

I am stuck with a problem of unnecessary scroll in the page and i tried with various option like : Overflow:'hidden' but the problem is other JS component which are wrapped in the same class are looking good:

code with file name MapHome file:

I have consulted many answers, but I still haven’t found the best way to implement it.

Now my case is to implement a multi map container, code below:

I am trying to achieve to refactor the below code into java8 using stream. How I can get the value of for any particular key in the hashmap Please suggest.

Running Python 3.9 in Windows 10. Python installed via Windows 10 Store. PATH environment has directory with file being executed.

I'm running the following code from Chapter 12 of Automate the Boring Stuff, a google map launcher:

I have a custom templated container using a map and list being kept in sync. The map needs to hold MyList::const_iterator and the list needs to hold MyMap::const_iterator. The only solution I've been able to find is to pun one of the iterators, as in the example below.

Is there a proper way to forward declare this so that I don't need the ugly punning?

Runnable code available at http://coliru.stacked-crooked.com/a/a5eae03ad5090b27.

(There are definitely other approaches that could be used for the example, but that's out of scope. This is a snippet of a larger program. I'm simply trying to make this "circular" definition without UB.)