Context context;

bool flag = false;

for (int i = 0; i < 100; i++) {

for (int j = 0; j < 100; j++) {

for (int k = 0; k < 100; k++) {

updateContext(i,j,k,context); if ( shouldBreak( context, i,j,k) ) {

flag = true;

break;

}

}

if (flag) break;

}

if (flag) break;

}

Here we've wrapped all other data that is changing into a context object that is updated every iteration, and is tested against.
So how can we make this "neat" .. here's one kind of solution.
bool flag = false;

for (int i = 0; i < 100; i++) {

for (int j = 0; j < 100; j++) {

for (int k = 0; k < 100; k++) {

updateContext(i,j,k,context); if ( shouldBreak( context, i,j,k) ) {

flag = true;

break;

}

}

if (flag) break;

}

if (flag) break;

}

void loopfn(Context & context)

{

for (int i = 0; i < 100; i++) {

for (int j = 0; j < 100; j++) {

for (int k = 0; k < 100; k++) {

updateContext(i,j,k,context);

if ( shouldBreak( context, i,j,k) ) return;

}

}

}

}

};

Context context;

loopfn(context);

One further step that can be helpful in further refactoring is:
{

for (int i = 0; i < 100; i++) {

for (int j = 0; j < 100; j++) {

for (int k = 0; k < 100; k++) {

updateContext(i,j,k,context);

if ( shouldBreak( context, i,j,k) ) return;

}

}

}

}

};

Context context;

loopfn(context);

class Looper

{

Looper(Context & c) : context(c) {}

Context context;

bool shouldBreak(int i,int k,int k);

void updateContext(int i,int k,int k);

void loop()

{

for (int i = 0; i < 100; i++) {

for (int j = 0; j < 100; j++) {

for (int k = 0; k < 100; k++) {

updateContext();

if ( shouldBreak(i,j,k) ) return;

}

}

}

}

};

Context context;

Looper l(context);

l.loop();

IMHO this is easier to maintain than the original loop with flags and breaks.
This is usually handy as we can make the updateContext and shouldBreak functions members of the Looper class.
Of course in most cases this can be refactored to be even neater, depending on what your context is.
{

Looper(Context & c) : context(c) {}

Context context;

bool shouldBreak(int i,int k,int k);

void updateContext(int i,int k,int k);

void loop()

{

for (int i = 0; i < 100; i++) {

for (int j = 0; j < 100; j++) {

for (int k = 0; k < 100; k++) {

updateContext();

if ( shouldBreak(i,j,k) ) return;

}

}

}

}

};

Context context;

Looper l(context);

l.loop();