let
  ensureAttrset = context: value:
    if builtins.isAttrs value then
      value
    else
      throw "${context} must be an attrset.";

  ensureString = context: value:
    if builtins.isString value then
      value
    else
      throw "${context} must be a string.";

  ensureNonEmptyString = context: value:
    if builtins.isString value && value != "" then
      value
    else
      throw "${context} must be a non-empty string.";

  ensureInt = context: value:
    if builtins.isInt value then
      value
    else
      throw "${context} must be an int.";

  ensureList = context: value:
    if builtins.isList value then
      value
    else
      throw "${context} must be a list.";
in
rec {
  inherit ensureAttrset ensureString ensureNonEmptyString ensureInt ensureList;
}