Dear all,

I hope runtime safe `numeric_cast` can be added to standard library header <numeric>. 

The boost library has already got such feature,  I wonder if there  is already a proposal to merge it into the next standard?  

Before I searched and reached Boost::numeric_cast, I reinvented the wheel, together with some other helper functions. More technical details are written in markdown at: 
https://github.com/qingfengxia/cpp_numeric_cast/blob/master/proposal_numeric_cast.md

I have another idea: reuse the `explicit` keyword to prevent implicit conversion of function parameter. https://github.com/qingfengxia/cpp_numeric_cast/blob/master/proposal_explicit.md  I am not sure it is the correct maillist to discuss this idea. It proposes to change compiler code-base/hehaviors.  Please advise, shall I send another email somewhere else for this idea?

Demo code and implementation are hosted at:   https://github.com/qingfengxia/cpp_numeric_cast

Both ideas are at the "Float the idea" stage, all the code and text are in early draft condition.  They will be update and improve gradually. 

Thank you and looking forwards to feedback.

Yours Sincerely,

Qingfeng Xia