__var_set() {
  if __is_eq "$1" "--value"; then
    read vname && vval="$2"
  elif __is_eq "$1" "--name"; then
    read vval && vname="$2"
  else
    vname="$1" && vval="$2"
  fi

  echo "Name: $vname , Value: $vval"
  eval "$vname"="$vval"
}

# This part works as expected...

__var_set "name" "value" && echo "$value"
# Outputs 'Name: name , Value: value'
echo "nametwo" | __var_set --value "valuetwo"
# Outputs 'Name: nametwo , Value: valuetwo'

# ...however...

echo "$name"         # Outputs "value"
echo "$nametwo"      # Outputs ""