Replace std::endl with '\n'

README.md

@@ -194,9 +194,9 @@ int main() {
   }
 
   // Total number of terms (monomials) in 'H'.
-  std::cout << "Total number of terms in H: " << H.size() << std::endl;
+  std::cout << "Total number of terms in H: " << H.size() << '\n';
   // Is H Hermitian?
-  std::cout << "H^\\dagger - H = " << (conj(H) - H) << std::endl;
+  std::cout << "H^\\dagger - H = " << (conj(H) - H) << '\n';
 
   // Does H commute with N and S_z?
   decltype(H) N, S_z;
@@ -206,8 +206,8 @@ int main() {
       S_z += 0.5 * (n(ix, iy, "up") - n(ix, iy, "down"));
     }
   }
-  std::cout << "[H, N] = " << (H * N - N * H) << std::endl;
-  std::cout << "[H, S_z] = " << (H * S_z - S_z * H) << std::endl;
+  std::cout << "[H, N] = " << (H * N - N * H) << '\n';
+  std::cout << "[H, S_z] = " << (H * S_z - S_z * H) << '\n';
 
   // Iterate over all terms in 'H' and print those of degree 3.
   //
@@ -216,7 +216,7 @@ int main() {
   for(auto const& term: H) {
     if(term.monomial.size() == 3) {
       // term.coeff is coefficient in front of the monomial
-      std::cout << term.monomial << " => " << term.coeff << std::endl;
+      std::cout << term.monomial << " => " << term.coeff << '\n';
     }
   }
 
@@ -258,12 +258,12 @@ int main() {
   auto H = 0.5 * (S_p(1) * S_m(2) + S_m(1) * S_p(2)) + S_z(1) * S_z(2);
 
   // Print 'H'
-  std::cout << "H = " << H << std::endl;
+  std::cout << "H = " << H << '\n';
 
   // Automatically analyze structure of 'H' and construct a 4-dimensional
   // Hilbert space (direct product of two spin-1/2 spaces).
   auto hs = make_hilbert_space(H);
-  std::cout << "dim(hs) = " << hs.dim() << std::endl;
+  std::cout << "dim(hs) = " << hs.dim() << '\n';
 
   // Construct a 'loperator' object that represents action of expression 'H' on
   // state vectors in the Hilbert space 'hs'.
@@ -291,7 +291,7 @@ int main() {
     for(int j = 0; j < 4; ++j) {
       std::cout << "+(" << phi[j] << ")|" << j << ">";
     }
-    std::cout << std::endl;
+    std::cout << '\n';
   }
 
   return 0;

doc/expression/expression.rst

@@ -489,7 +489,7 @@ This allows for writing complex expression analysis algorithms.
         }
 
       }
-      std::cout << std::endl;
+      std::cout << '\n';
     }
 
 .. note:: Only the constant iterators are implemented by :type:`expression` and
@@ -531,7 +531,7 @@ taken to be different on odd and even chain links.
       H += v * (c_dag(a) * c(a + 1) + c_dag(a + 1) * c(a));
     }
 
-    std::cout << "H = " << H << std::endl;
+    std::cout << "H = " << H << '\n';
 
     // Construct the Su-Schrieffer-Heeger (SSH) model by changing hopping
     // constants on all even links of the chain.
@@ -557,7 +557,7 @@ taken to be different on odd and even chain links.
 
     auto H_SSH = transform(H, update_hopping_element);
 
-    std::cout << "H_SSH = " << H_SSH << std::endl;
+    std::cout << "H_SSH = " << H_SSH << '\n';
 
 .. _hc:
 

doc/expression/generator.rst

@@ -332,7 +332,7 @@ In other words,
   // or annihilation operator.
   if(is_fermion(g)) {
     auto const& f = dynamic_cast<generator_fermion<int, std::string> const&>(g);
-    std::cout << (f.dagger() ? "creation" : "annihilation") << std::endl;
+    std::cout << (f.dagger() ? "creation" : "annihilation") << '\n';
   }
 
 .. _generator_boson:
@@ -416,7 +416,7 @@ In other words,
   // annihilation operator.
   if(is_boson(g)) {
     auto const& b = dynamic_cast<generator_boson<int> const&>(g);
-    std::cout << (b.dagger() ? "creation" : "annihilation") << std::endl;
+    std::cout << (b.dagger() ? "creation" : "annihilation") << '\n';
   }
 
 .. _generator_spin:
@@ -573,17 +573,17 @@ In other words,
   if(is_spin(g)) {
     auto const& s = dynamic_cast<generator_spin<int> const&>(g);
 
-    std::cout << "J = " << s.spin() << std::endl;
-    std::cout << "2J+1 = " << s.multiplicity() << std::endl;
+    std::cout << "J = " << s.spin() << '\n';
+    std::cout << "2J+1 = " << s.multiplicity() << '\n';
     switch(s.component()) {
       case libcommute::plus:
-        std::cout << "+" << std::endl;
+        std::cout << "+\n";
         break;
       case libcommute::minus:
-        std::cout << "-" << std::endl;
+        std::cout << "-\n";
         break;
       case libcommute::z:
-        std::cout << "z" << std::endl;
+        std::cout << "z\n";
         break;
     }
   }

examples/exchange_matrix.cpp

@@ -40,12 +40,12 @@ int main() {
   auto H = 0.5 * (S_p(1) * S_m(2) + S_m(1) * S_p(2)) + S_z(1) * S_z(2);
 
   // Print 'H'
-  std::cout << "H = " << H << std::endl;
+  std::cout << "H = " << H << '\n';
 
   // Automatically analyze structure of 'H' and construct a 4-dimensional
   // Hilbert space (direct product of two spin-1/2 spaces).
   auto hs = make_hilbert_space(H);
-  std::cout << "dim(hs) = " << hs.dim() << std::endl;
+  std::cout << "dim(hs) = " << hs.dim() << '\n';
 
   // Construct a 'loperator' object that represents action of expression 'H' on
   // state vectors in the Hilbert space 'hs'.
@@ -75,7 +75,7 @@ int main() {
     for(int j = 0; j < 4; ++j) {
       std::cout << "+(" << phi[j] << ")|" << j << ">";
     }
-    std::cout << std::endl;
+    std::cout << '\n';
   }
 
   return 0;

examples/gamma.expression.cpp

@@ -40,7 +40,7 @@ int main() {
       std::cout << "{" << gamma_mu << ", " << gamma_nu << "}"
                 << " - 2\\eta(" << mu << ", " << nu << "} = "
                 << (gamma_mu * gamma_nu + gamma_nu * gamma_mu - 2 * eta(mu, nu))
-                << std::endl;
+                << '\n';
     }
   }
 
@@ -50,13 +50,12 @@ int main() {
       I * make_gamma(0) * make_gamma(1) * make_gamma(2) * make_gamma(3);
 
   // \gamma^5 is Hermitian ...
-  std::cout << "gamma5 - conj(gamma5) = " << (gamma5 - conj(gamma5))
-            << std::endl;
+  std::cout << "gamma5 - conj(gamma5) = " << (gamma5 - conj(gamma5)) << '\n';
 
   // ... and anti-commutes with \gamma^\mu.
   for(int mu = 0; mu < 4; ++mu) {
     auto gamma_mu = make_gamma(mu);
     std::cout << "{gamma5, " << gamma_mu
-              << "} = " << (gamma5 * gamma_mu + gamma_mu * gamma5) << std::endl;
+              << "} = " << (gamma5 * gamma_mu + gamma_mu * gamma5) << '\n';
   }
 }

examples/gamma.loperator.cpp

@@ -185,7 +185,7 @@ int main() {
     for(int j = 0; j < 4; ++j) {
       std::cout << "+" << phi[j] << "|" << j << ">";
     }
-    std::cout << std::endl;
+    std::cout << '\n';
   }
 
   return 0;

examples/heisenberg_chain.cpp

@@ -85,16 +85,16 @@ int main() {
     S_tot = S_tot + S[i];
 
   // All three components of S commute with the Hamiltonian.
-  std::cout << "[H, S_x] = " << (H * S_tot[0] - S_tot[0] * H) << std::endl;
-  std::cout << "[H, S_y] = " << (H * S_tot[1] - S_tot[1] * H) << std::endl;
-  std::cout << "[H, S_z] = " << (H * S_tot[2] - S_tot[2] * H) << std::endl;
+  std::cout << "[H, S_x] = " << (H * S_tot[0] - S_tot[0] * H) << '\n';
+  std::cout << "[H, S_y] = " << (H * S_tot[1] - S_tot[1] * H) << '\n';
+  std::cout << "[H, S_z] = " << (H * S_tot[2] - S_tot[2] * H) << '\n';
 
   // Higher charge Q_3 (1st line of Eq. (10)).
   expr_t Q3;
   for(int i = 0; i < N; ++i) {
     Q3 += dot(cross(S[i], S[(i + 1) % N]), S[(i + 2) % N]);
   }
-  std::cout << "[H, Q3] = " << (H * Q3 - Q3 * H) << std::endl;
+  std::cout << "[H, Q3] = " << (H * Q3 - Q3 * H) << '\n';
 
   // Higher charge Q_4 (2nd line of Eq. (10)).
   expr_t Q4;
@@ -103,7 +103,7 @@ int main() {
                     S[(i + 3) % N]);
     Q4 += dot(S[i], S[(i + 2) % N]);
   }
-  std::cout << "[H, Q4] = " << (H * Q4 - Q4 * H) << std::endl;
+  std::cout << "[H, Q4] = " << (H * Q4 - Q4 * H) << '\n';
 
   // Higher charge Q_5 (3rd line of Eq. (10)).
   expr_t Q5;
@@ -114,12 +114,12 @@ int main() {
     Q5 += dot(cross(S[i], S[(i + 2) % N]), S[(i + 3) % N]);
     Q5 += dot(cross(S[i], S[(i + 1) % N]), S[(i + 3) % N]);
   }
-  std::cout << "[H, Q5] = " << (H * Q5 - Q5 * H) << std::endl;
+  std::cout << "[H, Q5] = " << (H * Q5 - Q5 * H) << '\n';
 
   // Check that the higher charges pairwise commute.
-  std::cout << "[Q3, Q4] = " << (Q3 * Q4 - Q4 * Q3) << std::endl;
-  std::cout << "[Q3, Q5] = " << (Q3 * Q5 - Q5 * Q3) << std::endl;
-  std::cout << "[Q4, Q5] = " << (Q4 * Q5 - Q5 * Q4) << std::endl;
+  std::cout << "[Q3, Q4] = " << (Q3 * Q4 - Q4 * Q3) << '\n';
+  std::cout << "[Q3, Q5] = " << (Q3 * Q5 - Q5 * Q3) << '\n';
+  std::cout << "[Q4, Q5] = " << (Q4 * Q5 - Q5 * Q4) << '\n';
 
   return 0;
 }

examples/holstein.cpp

@@ -120,10 +120,10 @@ int main() {
   auto H_H = H_e + H_ph + H_e_ph;
 
   // Print H_H. There will be quite a lot of terms for the 100-site lattice!
-  std::cout << "H_H = " << H_H << std::endl;
+  std::cout << "H_H = " << H_H << '\n';
 
   // Check hermiticity of H_H
-  std::cout << "H_H - H_H^\\dagger = " << (H_H - conj(H_H)) << std::endl;
+  std::cout << "H_H - H_H^\\dagger = " << (H_H - conj(H_H)) << '\n';
 
   // Check that H_H commutes with the total number of electrons
   decltype(H_H) N_e;
@@ -135,7 +135,7 @@ int main() {
     }
   }
 
-  std::cout << "[H_H, N_e] = " << (H_H * N_e - N_e * H_H) << std::endl;
+  std::cout << "[H_H, N_e] = " << (H_H * N_e - N_e * H_H) << '\n';
 
   return 0;
 }

examples/hubbard_holstein.cpp

@@ -115,9 +115,9 @@ int main() {
   }
 
   // Total number of terms (monomials) in 'H'.
-  std::cout << "Total number of terms in H: " << H.size() << std::endl;
+  std::cout << "Total number of terms in H: " << H.size() << '\n';
   // Is H Hermitian?
-  std::cout << "H^\\dagger - H = " << (conj(H) - H) << std::endl;
+  std::cout << "H^\\dagger - H = " << (conj(H) - H) << '\n';
 
   // Does H commute with N and S_z?
   decltype(H) N, S_z;
@@ -127,8 +127,8 @@ int main() {
       S_z += 0.5 * (n(ix, iy, "up") - n(ix, iy, "down"));
     }
   }
-  std::cout << "[H, N] = " << (H * N - N * H) << std::endl;
-  std::cout << "[H, S_z] = " << (H * S_z - S_z * H) << std::endl;
+  std::cout << "[H, N] = " << (H * N - N * H) << '\n';
+  std::cout << "[H, S_z] = " << (H * S_z - S_z * H) << '\n';
 
   // Iterate over all terms in 'H' and print those of degree 3.
   //
@@ -137,7 +137,7 @@ int main() {
   for(auto const& term : H) {
     if(term.monomial.size() == 3) {
       // term.coeff is coefficient in front of the monomial
-      std::cout << term.monomial << " => " << term.coeff << std::endl;
+      std::cout << term.monomial << " => " << term.coeff << '\n';
     }
   }
 

examples/jaynes_cummings.cpp

@@ -52,7 +52,7 @@ int main() {
 
   // Check that the number operator commutes with the Hamiltonian
   auto N = a_dag() * a() + S_z();
-  std::cout << "[H, N] = " << (H * N - N * H) << std::endl;
+  std::cout << "[H, N] = " << (H * N - N * H) << '\n';
 
   // Complete Hilbert space of the system is a product of the isospin-1/2 space
   // and the bosonic space truncated to 2^10 - 1 excitations.
@@ -106,8 +106,7 @@ int main() {
   psi = Hop(phi);
 
   // Check |\psi> \approx E_{gs} |\phi>
-  std::cout << "|||0,g> - E_g|0,g>||_{L^2} = " << diff(psi, phi, E_gs)
-            << std::endl;
+  std::cout << "|||0,g> - E_g|0,g>||_{L^2} = " << diff(psi, phi, E_gs) << '\n';
 
   //
   // Now, do a similar check for the Jaynes-Cummings ladder doublets.
@@ -131,7 +130,7 @@ int main() {
     psi = Hop(phi);
 
     std::cout << "|||" << n << ",+> - E_+(" << n << ")|" << n
-              << ",+>||_{L^2} = " << diff(psi, phi, energy(1, n)) << std::endl;
+              << ",+>||_{L^2} = " << diff(psi, phi, energy(1, n)) << '\n';
 
     // Set \phi to be the "-" dressed state
     std::fill(phi.begin(), phi.end(), 0);
@@ -141,7 +140,7 @@ int main() {
     psi = Hop(phi);
 
     std::cout << "|||" << n << ",-> - E_-(" << n << ")|" << n
-              << ",->||_{L^2} = " << diff(psi, phi, energy(-1, n)) << std::endl;
+              << ",->||_{L^2} = " << diff(psi, phi, energy(-1, n)) << '\n';
   }
 
   return 0;

examples/kanamori.cpp

@@ -86,7 +86,7 @@ int main() {
   }
 
   // Print the Hamiltonian
-  std::cout << "H_K = " << H_K << std::endl;
+  std::cout << "H_K = " << H_K << '\n';
 
   //
   // Integrals of motion N, S^2 and L^2 (Eq. (4)).
@@ -142,7 +142,7 @@ int main() {
                (5.0 / 2) * J * N;
 
   // Must be zero
-  std::cout << "H_K - H_t2g = " << (H_K - H_t2g) << std::endl;
+  std::cout << "H_K - H_t2g = " << (H_K - H_t2g) << '\n';
 
   return 0;
 }

examples/n_fermion_sectors.cpp

@@ -103,7 +103,7 @@ int main() {
 
   // Automatically analyze structure of 'H' and construct a Hilbert space
   auto hs = make_hilbert_space(H);
-  std::cout << "Full Hilbert space dimension: " << hs.dim() << std::endl;
+  std::cout << "Full Hilbert space dimension: " << hs.dim() << '\n';
 
   // Construct a 'loperator' object that represents action of expression 'H' on
   // state vectors in the Hilbert space 'hs'.
@@ -117,7 +117,7 @@ int main() {
     int const N = 2;
 
     auto const sector_size = n_fermion_sector_size(hs, N);
-    std::cout << "Size of the N = 2 sector: " << sector_size << std::endl;
+    std::cout << "Size of the N = 2 sector: " << sector_size << '\n';
 
     // Preallocate a Hamiltonian matrix to be filled and diagonalized.
     // Note that we have to store matrix elements only within the small sector.
@@ -148,7 +148,7 @@ int main() {
                                                         Eigen::EigenvaluesOnly);
 
     std::cout << "10 lowest eigenvalues of the N = 2 sector: "
-              << diag.eigenvalues().head(10).transpose() << std::endl;
+              << diag.eigenvalues().head(10).transpose() << '\n';
   }
 
   //
@@ -175,7 +175,7 @@ int main() {
 
     auto const multisector_size = n_fermion_multisector_size(hs, sectors);
     std::cout << "Size of the N_up = 1, N_down = 1 multisector: "
-              << multisector_size << std::endl;
+              << multisector_size << '\n';
 
     // Preallocate a Hamiltonian matrix to be filled and diagonalized.
     // Note that we have to store matrix elements only within the multisector.
@@ -206,7 +206,7 @@ int main() {
                                                         Eigen::EigenvaluesOnly);
 
     std::cout << "10 lowest eigenvalues of the multisector: "
-              << diag.eigenvalues().head(10).transpose() << std::endl;
+              << diag.eigenvalues().head(10).transpose() << '\n';
   }
 
   return 0;

examples/parametric_loperator.cpp

@@ -168,7 +168,7 @@ int main() {
     for(unsigned int i = 0; i < ket.size(); ++i) {
       if(ket[i] != 0) std::cout << " +(" << ket[i] << ")|" << i << ">";
     }
-    std::cout << std::endl;
+    std::cout << '\n';
   }
 
   return 0;