bench_float_parsing | Full disclosure for http

I am sorry to not exactly answer your question. But boost spirit is not the appropriate tool. Spirit is a parser generator (as a subset is does of course also lexical analysis) . So, one level to high in the Chomsky hiearchy of languages. You do not need a parser but regular expressions: std:regex

A double can easily be found with a regular expression. In the attached code, I created a simple pattern for a doubles. And a regex can be used to search for it.

So, we will read from an istream (what can be a file, a stringstream, console input or whatever). We will read line by line, until the whole input is consumed.

For each line, we will check, if the input matches the expected pattern, being 1 double.

Then we read this double, do some calculations and then push it into the vector.

Please see the following very simple code.