It seems that there's a particular behaviour that tells the DropdownToggle component (and maybe others) to use the children as "master button" if there's a single one, instead of creating a new one. I feel like it's a mistake:

• It's not an intuitive behaviour - without looking at the source code, one might wonder what happens (I sure did)

• The tag prop already allows us to customize the way the button is rendered, and is much more idomatic than adding props to already-rendered components.

• It makes it quite harder to use icons inside a DropdownToggle (because the icon props are rewritten, so the classNames are lost). For example, the following doesn't work:

  <DropdownToggle>
      <i className={`fa fa-user`} />
  </DropdownToggle>

  One has to write the following:

  <DropdownToggle>
      <i className={`fa fa-user`} /> <span></span>
  </DropdownToggle>

  In order to bypass the check.

• Additional issues may arise (for example, without testing, I guess that such a pattern also breaks refs, and triggers more renders than required).

Would you consider removing this behaviour?