I am working on a project were I have to read line form ( PLC ) programmable logic controller generated text file with lines like this

Circuit Value Current 2.33 4.32 5.55
there could be up to 3000 lines per txt file

I am using string stream to parse the line , for the sake of good programming I which to check weather first three values are string and last three values are actually floats
raise or throw an exception if they are not , any help in this regard would be much appreciated .