Listing 8.3 - Compiler Error

[ITHelpDec]

Issues

1. Two headers are missing (<numeric> and <functional>)
2. Our std::packaged_task is constructed incorrectly (requires extra parentheses)
3. The default constructor for accumulate_block is mistakenly called in place of accumulate_block<Iterator,T>::operator()

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Stylistically it might also be nice to replace lines 50-51...

ccia_code_samples/listings/listing_8.3.cpp

Lines 50 to 51 in 6e7ae1d

	std::for_each(threads.begin(),threads.end(),
	std::mem_fn(&std::thread::join));

... with a range-based for loop.

for (auto &t : threads) { t.join(); }

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Tested successfully on gcc, clang and apple clang.