Problem with std::map management
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Hi. I have a problem managing access to the map. In my project, I added a file:
HeaderVariablesContent.h
HeaderVariablesContent.cppIn header file I added:
extern std::map<EAutoCADVersionNumber, std::string> oAutoCADVersionNumberMap;In cpp:
std::map<EAutoCADVersionNumber, std::string> oAutoCADVersionNumberMap = { { EAutoCADVersionNumber::eR10, oAutoCADVersionNumberVector[0]}, { EAutoCADVersionNumber::eR11, oAutoCADVersionNumberVector[1]}, { EAutoCADVersionNumber::eR12, oAutoCADVersionNumberVector[1]}, { EAutoCADVersionNumber::eR13, oAutoCADVersionNumberVector[2]}, { EAutoCADVersionNumber::eR14, oAutoCADVersionNumberVector[3]}, { EAutoCADVersionNumber::eAutoCAD2000, oAutoCADVersionNumberVector[4]}, { EAutoCADVersionNumber::eAutoCAD2004, oAutoCADVersionNumberVector[5]}, { EAutoCADVersionNumber::eAutoCAD2007, oAutoCADVersionNumberVector[6]}, { EAutoCADVersionNumber::eAutoCAD2010, oAutoCADVersionNumberVector[7]}, { EAutoCADVersionNumber::eAutoCAD2013, oAutoCADVersionNumberVector[8]}, { EAutoCADVersionNumber::eAutoCAD2018, oAutoCADVersionNumberVector[9]}, };The key and value of the map are added in HeaderVariablesDef.h
extern std::vector<std::string> oAutoCADVersionNumberVector; enum class EAutoCADVersionNumber{ eR10, eR11, eR12, eR13, eR14, eAutoCAD2000, eAutoCAD2004, eAutoCAD2007, eAutoCAD2010, eAutoCAD2013, eAutoCAD2018, };And HeaderVariablesDef.cpp
std::vector<std::string> oAutoCADVersionNumberVector = { "AC1006", "AC1009", "AC1012", "AC1014", "AC1015", "AC1018", "AC1021", "AC1024", "AC1027", "AC1032" };In main.cpp I want to display map element but I got the error:
libc++abi: terminating due to uncaught exception of type std::out_of_range: vectorI'm not sure what it comes from. I think the code is written correctly. If anyone has any suggestions, I will be grateful.
Have a good day
BushyAxis793@BushyAxis793
Run under debugger and see where the "out of range" comes from. Somewhere you are trying to access an element of avectorwhere the index is either below 0 or greater than [Edited to keep @SamiV123 happy: OR EQUAL TO!] the item count. -
@BushyAxis793
Run under debugger and see where the "out of range" comes from. Somewhere you are trying to access an element of avectorwhere the index is either below 0 or greater than [Edited to keep @SamiV123 happy: OR EQUAL TO!] the item count.@JonB said in Problem with std::map management:
@BushyAxis793
Run under debugger and see where the "out of range" comes from. Somewhere you are trying to access an element of avectorwhere the index is either below 0 or greater than the item count.Except that std::vector's index type is unsigned so you can't access below 0 and accessing the index at item count is already undefined.
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@JonB said in Problem with std::map management:
@BushyAxis793
Run under debugger and see where the "out of range" comes from. Somewhere you are trying to access an element of avectorwhere the index is either below 0 or greater than the item count.Except that std::vector's index type is unsigned so you can't access below 0 and accessing the index at item count is already undefined.
accessing the index at item count is already undefined.
Meaning what? It will give
std::out_of_range: vector. Which is what the user sees.I don't see why we disagreeing here. In general the way to see where such an error occurs is under a debugger.
Yes, if there is no other code it may well be that
oAutoCADVersionNumberMap = {is evaluated/executed beforeoAutoCADVersionNumberVector = {and that is the cause of the error. What harm does it do to check this under debugger? -
Are those global objects? The construction order is undefined.
@SamiV123 Yes, global.
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accessing the index at item count is already undefined.
Meaning what? It will give
std::out_of_range: vector. Which is what the user sees.I don't see why we disagreeing here. In general the way to see where such an error occurs is under a debugger.
Yes, if there is no other code it may well be that
oAutoCADVersionNumberMap = {is evaluated/executed beforeoAutoCADVersionNumberVector = {and that is the cause of the error. What harm does it do to check this under debugger?@JonB said in Problem with std::map management:
accessing the index at item count is already undefined.
Meaning what? It will give
std::out_of_range: vector. Which is what the user sees.I don't see why we disagreeing here. In general the way to see where such an error occurs is under a debugger.
Yes, if there is no other code it may well be that
oAutoCADVersionNumberMap = {is evaluated/executed beforeoAutoCADVersionNumberVector = {and that is the cause of the error. What harm does it do to check this under debugger?actually the operator [] isn't required to be "safe".
so therefore if you have
std::vector<int> foo; foo[0];It's undefined behavior.
I was just pointing out that you can't access an element at the index that equals the size of the vector since the last valid index is size - 1 so your comment was incorrect.
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Gentlemen, I found a mistake. One of the vectors in another file had 204 instead of 205 elements. Sorry for the confusion. And thank you for your help!
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@SamiV123 Yes, global.
@BushyAxis793 said in Problem with std::map management:
@SamiV123 Yes, global.
Yeah, don't do that.
either make a function like this
std::vector<int> MyVec() { static std::vector<int> foo {... }; return foo; }or use global pointers and restructure your code not to rely on global object initialization.
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B BushyAxis793 has marked this topic as solved on
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@JonB said in Problem with std::map management:
accessing the index at item count is already undefined.
Meaning what? It will give
std::out_of_range: vector. Which is what the user sees.I don't see why we disagreeing here. In general the way to see where such an error occurs is under a debugger.
Yes, if there is no other code it may well be that
oAutoCADVersionNumberMap = {is evaluated/executed beforeoAutoCADVersionNumberVector = {and that is the cause of the error. What harm does it do to check this under debugger?actually the operator [] isn't required to be "safe".
so therefore if you have
std::vector<int> foo; foo[0];It's undefined behavior.
I was just pointing out that you can't access an element at the index that equals the size of the vector since the last valid index is size - 1 so your comment was incorrect.
@SamiV123 said in Problem with std::map management:
I was just pointing out that you can't access an element at the index that equals the size of the vector since the last valid index is size - 1 so your comment was incorrect.
I don't know what you are on about or why you just seem to want to argue. Of course everyone knows "the last valid index is size - 1". My comment was not incorrect, I said just that. Are you quibbling over the fact that I wrote "or greater than the item count." when I could have written "greater than or equal to the item count." but didn't because I was trying to give the idea typing quickly, is that it? It doesn't matter whether you try to access
[10]or[1000000]in avectorwhich has 10 elements, either one is "out of range". Why don't you actually try it and see whether you getuncaught exception of type std::out_of_range: vectorinstead of arguing semantics?OP writes
One of the vectors in another file had 204 instead of 205 elements.
Oh look, just what I said: trying to access an element one (or could have been more, but 1 here) beyond the number in a vector....
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@SamiV123 said in Problem with std::map management:
I was just pointing out that you can't access an element at the index that equals the size of the vector since the last valid index is size - 1 so your comment was incorrect.
I don't know what you are on about or why you just seem to want to argue. Of course everyone knows "the last valid index is size - 1". My comment was not incorrect, I said just that. Are you quibbling over the fact that I wrote "or greater than the item count." when I could have written "greater than or equal to the item count." but didn't because I was trying to give the idea typing quickly, is that it? It doesn't matter whether you try to access
[10]or[1000000]in avectorwhich has 10 elements, either one is "out of range". Why don't you actually try it and see whether you getuncaught exception of type std::out_of_range: vectorinstead of arguing semantics?OP writes
One of the vectors in another file had 204 instead of 205 elements.
Oh look, just what I said: trying to access an element one (or could have been more, but 1 here) beyond the number in a vector....
@JonB said in Problem with std::map management:
@SamiV123 said in Problem with std::map management:
I was just pointing out that you can't access an element at the index that equals the size of the vector since the last valid index is size - 1 so your comment was incorrect.
I don't know what you are on about or why you just seem to want to argue. Of course everyone knows "the last valid index is size - 1". My comment was not incorrect, I said just that. Are you quibbling over the fact that I wrote "or greater than the item count." when I could have written "greater than or equal to the item count." but didn't because I was trying to give the idea typing quickly, is that it? It doesn't matter whether you try to access
[10]or[1000000]in avectorwhich has 10 elements, either one is "out of range". Why don't you actually try it and see whether you getuncaught exception of type std::out_of_range: vectorinstead of arguing semantics?OP writes
One of the vectors in another file had 204 instead of 205 elements.
Oh look, just what I said: trying to access an element one (or could have been more, but 1 here) beyond the number in a vector....
I don't think everyone knows. It seems obvious that the OP is a newbie since if they weren't they would not have even posted this question.
So therefore they might have gone off the rails thinking that accessing the element at an off by one index is actually safe.
This is C++, you can't be "99%" correct you have to be 100% correct or your program is ill-defined. (which it always is anyway)
Thats all, peace out.
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@JonB said in Problem with std::map management:
@SamiV123 said in Problem with std::map management:
I was just pointing out that you can't access an element at the index that equals the size of the vector since the last valid index is size - 1 so your comment was incorrect.
I don't know what you are on about or why you just seem to want to argue. Of course everyone knows "the last valid index is size - 1". My comment was not incorrect, I said just that. Are you quibbling over the fact that I wrote "or greater than the item count." when I could have written "greater than or equal to the item count." but didn't because I was trying to give the idea typing quickly, is that it? It doesn't matter whether you try to access
[10]or[1000000]in avectorwhich has 10 elements, either one is "out of range". Why don't you actually try it and see whether you getuncaught exception of type std::out_of_range: vectorinstead of arguing semantics?OP writes
One of the vectors in another file had 204 instead of 205 elements.
Oh look, just what I said: trying to access an element one (or could have been more, but 1 here) beyond the number in a vector....
I don't think everyone knows. It seems obvious that the OP is a newbie since if they weren't they would not have even posted this question.
So therefore they might have gone off the rails thinking that accessing the element at an off by one index is actually safe.
This is C++, you can't be "99%" correct you have to be 100% correct or your program is ill-defined. (which it always is anyway)
Thats all, peace out.
@SamiV123 said in Problem with std::map management:
This is C++, you can't be "99%" correct you have to be 100% correct or your program is ill-defined. (which it always is anyway)
I will hold you to this in all your future posts, then ;-) [ <-- That's a wink! ]
For the record, I have edited my original post to be "100%" clear :)
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@JonB said in Problem with std::map management:
@SamiV123 said in Problem with std::map management:
I was just pointing out that you can't access an element at the index that equals the size of the vector since the last valid index is size - 1 so your comment was incorrect.
I don't know what you are on about or why you just seem to want to argue. Of course everyone knows "the last valid index is size - 1". My comment was not incorrect, I said just that. Are you quibbling over the fact that I wrote "or greater than the item count." when I could have written "greater than or equal to the item count." but didn't because I was trying to give the idea typing quickly, is that it? It doesn't matter whether you try to access
[10]or[1000000]in avectorwhich has 10 elements, either one is "out of range". Why don't you actually try it and see whether you getuncaught exception of type std::out_of_range: vectorinstead of arguing semantics?OP writes
One of the vectors in another file had 204 instead of 205 elements.
Oh look, just what I said: trying to access an element one (or could have been more, but 1 here) beyond the number in a vector....
I don't think everyone knows. It seems obvious that the OP is a newbie since if they weren't they would not have even posted this question.
So therefore they might have gone off the rails thinking that accessing the element at an off by one index is actually safe.
This is C++, you can't be "99%" correct you have to be 100% correct or your program is ill-defined. (which it always is anyway)
Thats all, peace out.
@SamiV123 It's funny that you're arguing with 100% correct c++ here but advertising a proprietary way to link against libraries ('# pragma comment(lib, "ws2_32.lib")') in another thread.
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@SamiV123 It's funny that you're arguing with 100% correct c++ here but advertising a proprietary way to link against libraries ('# pragma comment(lib, "ws2_32.lib")') in another thread.
@Christian-Ehrlicher said in Problem with std::map management:
@SamiV123 It's funny that you're arguing with 100% correct c++ here but advertising a proprietary way to link against libraries ('# pragma comment(lib, "ws2_32.lib")') in another thread.
Yeah and that's completely orthogonal to this here.
Using a compiler specific way to link your program doesn't make it ill-defined (just possibly non portable). -
@Christian-Ehrlicher said in Problem with std::map management:
@SamiV123 It's funny that you're arguing with 100% correct c++ here but advertising a proprietary way to link against libraries ('# pragma comment(lib, "ws2_32.lib")') in another thread.
Yeah and that's completely orthogonal to this here.
Using a compiler specific way to link your program doesn't make it ill-defined (just possibly non portable).@SamiV123 said in Problem with std::map management:
just possibly non portable
Which contradicts the c++ idea.
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@SamiV123 said in Problem with std::map management:
just possibly non portable
Which contradicts the c++ idea.
@Christian-Ehrlicher said in Problem with std::map management:
@SamiV123 said in Problem with std::map management:
just possibly non portable
Which contradicts the c++ idea.
Maybe so but that's not how real life works. In real life practically every C++ program is only as portable as the developers intended, i.e. it only compiles and runs on the platforms targeted by the developers.
