boost format operator % won't accept dereference of volatile

[paul.d.rose@…]

struct A{

A() : a(9) {} int a;

}; A a; A volatile *pva = &a;

std::cout << boost::format("%d") % pva->a << std::endl;

This worked in 1_54 but fails in 1_56 with error:

format/feed_args.hpp:135:47: error: invalid conversion from 'volatile void*' to 'const void*'

Can work around this with cast:

std::cout << boost::format("%d") % (int)pva->a << std::endl;

but should not have to. The appearance to the user is pass by value.

Running linux with g++ 4.6.2 and 4.8.2

[Daniel Krügler <daniel.kruegler@…>]

We recently run into the very same problem: Our logger internally delegates to boost::format and users complained that they cannot logging output for volatile variables.

[jim.king@…]

This is present in boost 1.59 using clang-3.8 (in development) as well. It happens with any numeric type, not just int. One workaround is to use a static_cast to the same type, stripping the volatile keyword.

[fgeorge@…]

I ran into the same issue in boost 1.61.0 using visual studio 2008 (msvc-9.0), with a volatile size_t. static_cast<size_t> is the current workaround i'm using.

[arnaud.richard@…]

Same issue in boost 1.63.0 using Linaro GCC 5.2-2015.11-2

[James E. King, III]

Issue moved to github: ​https://github.com/boostorg/format/issues/36