IsSafeToDeferFormatting - Convert.GetTypeCode is faster and better

[snakefoot]

Than GetType().IsPrimitive()

Logger Name	Messages	Size	Args	Threads	Loggers
NullLogger	50.000.000	64	3	1	1

Test Name	Time (ms)	Msgs/sec	GC2	GC1	GC0	CPU (ms)	Alloc (MB)
This PR (32 bit)	16.497	3.030.675	0	0	721	14.359	7.248,2
Master (32 bit)	17.514	2.854.764	0	0	726	16.203	7.248,2
This PR (64 bit)	15.437	3.238.959	0	0	489	14.468	14.114,7
Master (64 bit)	15.923	3.139.958	0	0	481	15.203	14.114,7

[codecov]

Codecov Report

Merging #2595 into master will decrease coverage by <1%.
The diff coverage is 100%.

@@           Coverage Diff           @@
##           master   #2595    +/-   ##
=======================================
- Coverage      81%     81%   -<1%     
=======================================
  Files         325     325            
  Lines       23918   23915     -3     
  Branches     3022    3021     -1     
=======================================
- Hits        19408   19394    -14     
- Misses       3693    3708    +15     
+ Partials      817     813     -4

[304NotModified]

Are we 100% sure it's the same? Don't expect a performance improvement then.

[snakefoot]

Are we 100% sure it's the same? Don't expect a performance improvement then.

No it is not the same, since it is faster and better (Recognizes DateTime, Enum and Decimal as immutable). Though it will have a side-effect incase some has created custom type that inherits from IConvertible. But only "primitive struct types" should do that.

This the source code of Convert.GetTypeCode:

        public static TypeCode GetTypeCode(object value) {
            if (value == null) return TypeCode.Empty;
            IConvertible temp = value as IConvertible;
            if (temp != null)
            {
                return temp.GetTypeCode();
            }
            return TypeCode.Object;
        }

There is a lot of internal compiler optimization when it comes to GetType() and IsPrimitive(), but at the end it finds an internal typecode, and does a bitwise operation to check if one of the simple types specified here:

https://msdn.microsoft.com/en-us/library/system.type.isprimitive(v=vs.110).aspx

[304NotModified]

thanks!