I don't have a link but you can search on the web. I have the .pdf on my computer.
From "A History of C++: 1979− 1991".
> In C with Classes, a dot was used to express membership of a class as well as expressing
selection of a member of a particular object. This had been the cause of some minor confusion and could also be used to construct ambiguous examples. To alleviate this, :: was introduced to mean membership of class and . was retained exclusively for membership of object.
It was taken from Algol68.
Then, this was reused for namespaces for consistency reason.
alt Hacker News
I don't have a link but you can search on the web. I have the .pdf on my computer.
From "A History of C++: 1979− 1991".
> In C with Classes, a dot was used to express membership of a class as well as expressing selection of a member of a particular object. This had been the cause of some minor confusion and could also be used to construct ambiguous examples. To alleviate this, :: was introduced to mean membership of class and . was retained exclusively for membership of object.
It was taken from Algol68.
Then, this was reused for namespaces for consistency reason.