Add support for exception free usage of library

[rickyviking]

As mentioned in issue 63, I understand the current behavior of the library is to throw an exception when trying to read a missing cell in a row.
I'd like to know if there's a safe way to check in advance and avoid running into the exception.
The reason is that I'm integrating the lib in a framework which disable exception handling by default.

[d99kris]

Hi @rickyviking - with ConverterParams one can specify pHasDefaultConverter = true which means failed conversions from string to number will default to a value (which may be customized using pDefaultFloat and pDefaultInteger). This will avoid throwing exceptions on failed conversions, for example when a cell is empty or has an invalid number. Not sure if this helps your use case?

[rickyviking]

Hi @d99kris, that's exactly what I've tried, but apparently if a cell is missing in a row, the exception is thrown before the conversion is attempted, right when trying to access a vector index which does not exists.

Say my file is:

value_one,value_two,value_three
1,2,3
4,5
6,7,8

I get an exception when trying to access the 3rd value of the second row, even when the default converted is set.
I'd like to intercept that case without running into an exception, as I have no control over the csv input file and exception are disabled in the project I'm integrating the library into.
Hope this clarifies the issue, Thank you

[d99kris]

Thanks, that clarifies the issue! 👍

Short-term I would probably suggest checking some other c++ csv library. I will look into how/if can be provided in rapidcsv given its current API design, but it might not be a quick response (just to set expectations right).

[rickyviking]

Thank you for setting the right expectations :)
Let's see what you find out, thanks

[d99kris]

I've changed the title to Add support for exception free usage of library to indicate that it would require adding a new feature. Unfortunately I haven't had time to look into this further so far, but I will leave the issue/discussion open.

[rickyviking]

Sounds good, will monitor for any changes in the future, thx