Use index/get instead of std::visit.

arbor-sim · Aug 14, 2023 · 55f93df · 55f93df
1 parent 217c776
commit 55f93df
Showing 1 changed file with 61 additions and 43 deletions.
diff --git a/arbor/cable_cell_param.cpp b/arbor/cable_cell_param.cpp
@@ -125,49 +125,67 @@ decor& decor::place(locset where, placeable what, cell_tag_type label) {
 }
 
 decor& decor::set_default(defaultable what) {
- std::visit(
- [this] (auto&& p) {
- using T = std::decay_t<decltype(p)>;
- if constexpr (std::is_same_v<init_membrane_potential, T>) {
- if (p.value.type() != iexpr_type::scalar) throw cable_cell_error{"Default values cannot have a scale."};
- defaults_.init_membrane_potential = *p.value.get_scalar();
- }
- else if constexpr (std::is_same_v<axial_resistivity, T>) {
- if (p.value.type() != iexpr_type::scalar) throw cable_cell_error{"Default values cannot have a scale."};
- defaults_.axial_resistivity = *p.value.get_scalar();
- }
- else if constexpr (std::is_same_v<temperature_K, T>) {
- if (p.value.type() != iexpr_type::scalar) throw cable_cell_error{"Default values cannot have a scale."};
- defaults_.temperature_K = *p.value.get_scalar();
- }
- else if constexpr (std::is_same_v<membrane_capacitance, T>) {
- if (p.value.type() != iexpr_type::scalar) throw cable_cell_error{"Default values cannot have a scale."};
- defaults_.membrane_capacitance = *p.value.get_scalar();
- }
- else if constexpr (std::is_same_v<init_int_concentration, T>) {
- if (p.value.type() != iexpr_type::scalar) throw cable_cell_error{"Default values cannot have a scale."};
- defaults_.ion_data[p.ion].init_int_concentration = *p.value.get_scalar();
- }
- else if constexpr (std::is_same_v<init_ext_concentration, T>) {
- if (p.value.type() != iexpr_type::scalar) throw cable_cell_error{"Default values cannot have a scale."};
- defaults_.ion_data[p.ion].init_ext_concentration = *p.value.get_scalar();
- }
- else if constexpr (std::is_same_v<init_reversal_potential, T>) {
- if (p.value.type() != iexpr_type::scalar) throw cable_cell_error{"Default values cannot have a scale."};
- defaults_.ion_data[p.ion].init_reversal_potential = *p.value.get_scalar();
- }
- else if constexpr (std::is_same_v<ion_reversal_potential_method, T>) {
- defaults_.reversal_potential_method[p.ion] = p.method;
- }
- else if constexpr (std::is_same_v<cv_policy, T>) {
- defaults_.discretization = std::forward<cv_policy>(p);
- }
- else if constexpr (std::is_same_v<ion_diffusivity, T>) {
- if (p.value.type() != iexpr_type::scalar) throw cable_cell_error{"Default values cannot have a scale."};
- defaults_.ion_data[p.ion].diffusivity = p.value.get_scalar();
- }
- },
- what);
+ // NOTE: the index/get approach is considerably faster than std::visit.
+ switch (what.index()) {
+ case 0: {
+ auto& p = std::get<init_membrane_potential>(what);
+ if (p.value.type() != iexpr_type::scalar) throw cable_cell_error{"Default values cannot have a scale."};
+ defaults_.init_membrane_potential = *p.value.get_scalar();
+ break;
+ }
+ case 1: {
+ auto& p = std::get<axial_resistivity>(what);
+ if (p.value.type() != iexpr_type::scalar) throw cable_cell_error{"Default values cannot have a scale."};
+ defaults_.axial_resistivity = *p.value.get_scalar();
+ break;
+ }
+ case 2: {
+ auto& p = std::get<temperature_K>(what);
+ if (p.value.type() != iexpr_type::scalar) throw cable_cell_error{"Default values cannot have a scale."};
+ defaults_.temperature_K = *p.value.get_scalar();
+ break;
+ }
+ case 3: {
+ auto& p = std::get<membrane_capacitance>(what);
+ if (p.value.type() != iexpr_type::scalar) throw cable_cell_error{"Default values cannot have a scale."};
+ defaults_.membrane_capacitance = *p.value.get_scalar();
+ break;
+ }
+ case 4: {
+ auto& p = std::get<ion_diffusivity>(what);
+ if (p.value.type() != iexpr_type::scalar) throw cable_cell_error{"Default values cannot have a scale."};
+ defaults_.ion_data[p.ion].diffusivity = p.value.get_scalar();
+ break;
+ }
+ case 5: {
+ auto& p = std::get<init_int_concentration>(what);
+ if (p.value.type() != iexpr_type::scalar) throw cable_cell_error{"Default values cannot have a scale."};
+ defaults_.ion_data[p.ion].init_ext_concentration = *p.value.get_scalar();
+ break;
+ }
+ case 6: {
+ auto& p = std::get<init_ext_concentration>(what);
+ if (p.value.type() != iexpr_type::scalar) throw cable_cell_error{"Default values cannot have a scale."};
+ defaults_.ion_data[p.ion].init_int_concentration = p.value.get_scalar();
+ break;
+ }
+ case 7: {
+ auto& p = std::get<init_reversal_potential>(what);
+ if (p.value.type() != iexpr_type::scalar) throw cable_cell_error{"Default values cannot have a scale."};
+ defaults_.ion_data[p.ion].init_reversal_potential = *p.value.get_scalar();
+ break;
+ }
+ case 8: {
+ auto& p = std::get<ion_reversal_potential_method>(what);
+ defaults_.reversal_potential_method[p.ion] = p.method;
+ break;
+ }
+ case 9:
+ defaults_.discretization = std::forward<cv_policy>(std::get<cv_policy>(what));
+ break;
+ default:
+ throw arbor_internal_error{"Unknown defaultable variant"};
+ }
  return *this;
 }