A simple single-header-only c++ library for reading in key/value pairs from text files to be 
used e.g. to easily specify settings/configuration in programs.

The text file must specifies key/value pairs separated by the '=' sign, e.g.:

  key1 = a_value

Values can be numbers, strings, arrays of numbers or arrays of strings:

  stringKey = some_word	    # comments are supported!

  numericKey = 1e-4

  arrayOfNumbers = [1,3,5e-3]

  arrayOfText = [first, second, third , 4] 

Comments can be insterted following the '#' character.


Use:

1. include the "reader.h" file.
  #include <reader.h>
2. Create a reader object: 
  Reader reader;

3. Read a text file: 
  reader.readSettings("test.txt");

4. Read in values :

try {
  string s = reader.getValueByKey<string>("stringKey");
  std::vector<float> = reader.getValueByKey<std::vector<float>>("keyName"); 

  if (reader.containsKey("OptionalKey) ){
    int optionalInt = reader.getValueByKey<int>("OptionalKey");
  }

  }catch(ReaderError e){
    e.printError();
}

5. Compile with a c++11 compatible compiler

Exceptions will be thrown when things don't work out. For example when trying to
read incompaible types. The thrown exception contains in addition to a convenience
print method the following data:
	1. Reason for exception.
	2. Name of input file..
	3. Line number in input file causing the exception.