CODEWITHSUNDEEP
c++linuxgccdebian
thassan
thassan

Reputation: 401

Where is the limit.h file that defines the template numeric_limits

So, I am trying to locate the limit.h file that has the numeric_limits defined. I seem to find all different flavors of the limit.h but not the defined one, as shown in http://en.cppreference.com/w/cpp/types/numeric_limits

I am on debian distro.

Here is what I have done so far. I created a main.cpp with only #include <limits> Did a g++ verbose build to find all the include path: g++ -v main.cpp -o tryout. Now I see that /usr/include and usr/lib has bunch of limits.h files. But none of them seem to have the template definition I am looking for

in /usr/include/
% find -name limits.h returns the following :
./c++/4.4/tr1/limits.h
./limits.h
./linux/limits.h

in /usr/lib
% find -name limits.h returns the following:
./perl5/Tk/pTk/compat/limits.h
./gcc/x86_64-linux-gnu/4.3/include-fixed/limits.h
./gcc/x86_64-linux-gnu/4.4/include-fixed/limits.h

So where is the std::numeric_limits template located. How do I find that file.

Upvotes: 1

Views: 3038

Answers (1)

Cubbi
Cubbi

Reputation: 47448

As the reference page shows, std::numeric_limits is defined in the header <limits>, not limits.h. You can find where it is by asking the preprocessor, for example:

~$ cat test.cc
#include <limits>

~$ g++ -E test.cc -o - | grep limits | grep gcc | tail -1
# 841 "/opt/swt/install/gcc-4.7.2/lib/gcc/x86_64-unknown-linux-gnu/4.7.2/../../../../include/c++/4.7.2/limits" 3

Upvotes: 2

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