Sort TDictionary

Question

I do not experience general collections. I need to sort a TDictionary.

type TSearchResult = TPair<Integer,double>; var target_results : TDictionary<Integer, double>; session_search_results : array[0..max_searches] of TArray<TSearchResult>; 

I sort using this code

  session_search_results[session_search_id]:= target_results.ToArray; TArray.Sort<TSearchResult>(session_search_results[session_search_id], TComparer<TSearchResult>.Construct( function(const L, R: TSearchResult): Integer begin Result := Round(R.Value - L.Value); end )); 

Why am I getting an access violation with this? What am I doing wrong?

complement:

If I iterate over an array using

  for i:= 0 to Length(session_search_results[session_search_id])-1 do MyDebug(IntToStr(session_search_results[session_search_id][i].Key)+' = value = ' + FloatToStr(session_search_results[session_search_id][i].Value)); 

I get the output:

 Debug Output: ==>CoreSearchText: array length=8<== Process TestApp.exe (2536) Debug Output: ==>100007 = value = 19,515<== Process TestApp.exe (2536) Debug Output: ==>100003 = value = 2,4<== Process TestApp.exe (2536) Debug Output: ==>100005 = value = 12<== Process TestApp.exe (2536) Debug Output: ==>100008 = value = 2,4<== Process TestApp.exe (2536) Debug Output: ==>100002 = value = 2,4<== Process TestApp.exe (2536) Debug Output: ==>100004 = value = 2,4<== Process TestApp.exe (2536) Debug Output: ==>100009 = value = 40,515<== Process TestApp.exe (2536) Debug Output: ==>100001 = value = 15<== Process TestApp.exe (2536) 

Using sorting Access violation violates the application. The array seems to be in order. What is the reason? Thanks!

Answer 1

This is apparently a code error in XE (also existing in XE2) with the updated shared record and optimization enabled.

This program reproduces the error:

 program Project1; {$APPTYPE CONSOLE} {$O+} uses Generics.Collections, Generics.Defaults, SysUtils; type TSearchResult = TPair<Integer, Integer>; function Compare(const L, R: TSearchResult): Integer; begin Result := R.Value - L.Value; end; var values: TArray<TSearchResult>; begin try SetLength(values, 3); TArray.Sort<TSearchResult>(values, TComparer<TSearchResult>.Construct(Compare)); except on E: Exception do Writeln(E.ClassName, ': ', E.Message); end; Readln; end. 

I reported this as QC # 106391 .

A possible solution is to add {$ O-} to the module containing the call to TArray <T> .Sort.