Reputation: 209
I am currently using Visual Studio Community 2017. From looking at the C++ Language Standards in the project properties, they only provide C++14 and C++17. Since my code was completed for a previous assignment using a compiler for C++11, I am unable to run my code using functions such as stoi. My question is if there is a way to add C++11 to the language standards for C++?
I am creating a DLL for a GUI, my initializations are:
#include <string>
#include "stdafx.h"
using namespace std;
Here I am creating a fraction class, the main errors follow in the ifstream:
istream& operator>>(istream& in, Fraction& f) {
string number;
in >> number; //read the number
size_t delimiter = number.find("/"); //find the delimiter in the string "/"
if (delimiter != string::npos) { //if delimiter is not empty
int n = stoi(number.substr(0, delimiter)); //set numerator from string to integer before the "/"
int d = stoi(number.substr(delimiter + 1)); //set denominator from string to integer after the "/"
if (d == 0) { //if denominator is 0
throw FractionException("Illegal denominator, cannot divide by zero."); //illegal argument throw
}
else if (n == 0 && d != 0) { //numerator is 0, then set values as zero fraction
f.numVal = 0;
f.denVal = 1;
}
else { //set the values into the fraction and normalize and reduce fraction to minimum
f.numVal = n;
f.denVal = d;
f.normalizeAndReduce(f.numVal, f.denVal);
}
}
else { //else if there is no delimiter it would be a single integer
f.numVal = stoi(number);
f.denVal = 1;
}
return in;
}
I am getting the following errors:
C2679: binary '>>': no operator found which takes a right-hand operator of type 'std::string"
C3861: 'stoi' identifier not found
This method worked perfectly fine in eclipse, not sure what I am doing wrong.
Upvotes: 18
Views: 37042
Reputation: 41127
The Visual C++ 2017 compiler is C++11/C++14 compliant with a few specific exceptions:
The compiler does not offer a specific C++11 mode and defaults to C++14, but that standard is fully inclusive of C++11. C++17 support is in progress, and requires you use the /std:c++17 or /std::c++latest
switch.
std::stoi
requires you include the appropriate header, specifically <string>>
Either you forgot to include that header -or- you didn't deal with the namespace
resolution (either explicitly as std::
or via using namespace std;
)
See C++17 Features And STL Fixes In VS 2017 15.3 for the latest status of C++11/C++14/C++17 standards conformance as of the VS 2017 (15.3 update)
UPDATED: For the latest on Visual C++ conformance, see Microsoft Docs.
Now that you have posted your code, I see that the problem has nothing to do with which standard is supported. Your problem is that you don't know the secrets of how Precompiled Headers work.
Change:
#include <string>
#include "stdafx.h"
to:
#include "stdafx.h"
#include <string>
-or- add #include <string>
to the precompiled header stdafx.h
directly.
See Creating Precompiled Header Files
Upvotes: 33
Reputation: 657
Microsoft I think has declared that
Note that there is no plan to add a C++11 switch. link
So there's not an explicit switch
Upvotes: 4
Reputation: 1
As an update to this, VS 2017, Update 9.4 (releasd Dec 2018) is now fully C++17 compliant.
Upvotes: 0