VS的版本号之间有一定的对应关系，比如：
vc16win64 对应 Visual Studio 16 2019

VS的所有预定义宏：https://learn.microsoft.com/en-us/cpp/preprocessor/predefined-macros

其中，VS的版本号是_MSC_VER，也可以用它来判断是不是MSVC

#if defined(_MSC_VER)
#define NOMINMAX
#pragma once
#endif

_MSC_VER的可能取值

_MSC_VER Defined as an integer literal that encodes the major and minor 
number elements of the compiler's version number. The major number is 
the first element of the period-delimited version number and the minor 
number is the second element. For example, if the version number of 
the Microsoft C/C++ compiler is 17.00.51106.1, the _MSC_VER macro 
evaluates to 1700. Enter cl /? at the command line to view the compiler's 
version number. This macro is always defined.

Visual Studio version,	_MSC_VER

Visual Studio 6.0	1200
Visual Studio .NET 2002 (7.0)	1300
Visual Studio .NET 2003 (7.1)	1310
Visual Studio 2005 (8.0)	1400
Visual Studio 2008 (9.0)	1500
Visual Studio 2010 (10.0)	1600
Visual Studio 2012 (11.0)	1700
Visual Studio 2013 (12.0)	1800
Visual Studio 2015 (14.0)	1900
Visual Studio 2017 RTW (15.0)	1910
Visual Studio 2017 version 15.3	1911
Visual Studio 2017 version 15.5	1912
Visual Studio 2017 version 15.6	1913
Visual Studio 2017 version 15.7	1914
Visual Studio 2017 version 15.8	1915
Visual Studio 2017 version 15.9	1916
Visual Studio 2019 RTW (16.0)	1920
Visual Studio 2019 version 16.1	1921
Visual Studio 2019 version 16.2	1922
Visual Studio 2019 version 16.3	1923
Visual Studio 2019 version 16.4	1924
Visual Studio 2019 version 16.5	1925
Visual Studio 2019 version 16.6	1926
Visual Studio 2019 version 16.7	1927
Visual Studio 2019 version 16.8	1928

Q：能否安装多个版本的VS？
A：可以，直接下载对应版本的Installer安装即可